NCERT Solutions for Class 11 Commerce Economics Chapter 13 Measures Of Central Tendency are provided here with simple step-by-step explanations. These solutions for Measures Of Central Tendency are extremely popular among Class 11 Commerce students for Economics Measures Of Central Tendency Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the NCERT Book of Class 11 Commerce Economics Chapter 13 are provided here for you for free. You will also love the ad-free experience on Meritnation’s NCERT Solutions. All NCERT Solutions for class Class 11 Commerce Economics are prepared by experts and are 100% accurate. Show Page No 103:Question 1(A):Fill in the blanks from the alternatives given in the bracket 1) ______ is a positional average. 2) The arithmetic mean of the following observation 4,
8, 12, 16, is ______. 3) Cumulative frequency is needed while finding the ______ of the distribution. 4) _______ is the item having highest frequency. 5) The second quartile is known as _______. 6) The values which divide the total number of observations into 10 equal parts are ______. 7) There are ______ deciles. 8) There are _____ percentiles. 9) The range of 10 20 30 40 is ______. 10) 25th percentile is equal to ______. Answer:1. Median is a positional average. 2. The arithmetic mean of the following observation 4, 8, 12, 16, is 10. X=Σ Xn X=4+8+12+164=404=10 3. Cumulative frequency is needed while finding the medianof the distribution. 4. Mode is the item having highest frequency. 5. Second quartile is known as median. 6. The values which divide the total number of observations into 10 equal parts are deciles. 7. There are 9 deciles 8. There are 99 percentiles. 9. The range of 10 20 30 40 is 30. 10. 25th percentile is equal to 1st quartile. Page No 103:Question 1(B):Match the following:
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i. The mode is the observation occurring maximum number of times or most frequently in a series. Page No 103:Question 1(C):State whether, the following statements are true or false and rewrite them. 1) Mode is the value having maximum frequency. 2) Median is not affected by extreme items. 3) Arithmetic mean is not based on all observations. 4) Mode can be calculated by mere inspection. 5) Mean is not rigidly defined. 6) First decile is greater than first quartile. Answer:1. The given statement is true. 2. The statement is true. 3. The given statement is false. 4. The given statement is absolutely true. 5. The given statement is false. 6. The given statement is false. Page No 103:Question 2(A):Define/Explain the following concepts. 1. Arithmetic mean Answer:1. Arithmetic mean - The arithmetic mean refers to the value calculated by dividing the sum of the values of the given items by the total number of items present in a series. Mathematically, it is measured as: X=x1+x2+x3+......+xnN Here, X is the arithmetic mean. 2. Median - The median is the middlemost value of a set of data when arranged in an array (ascending or descending). The median divides the data into two equal groups. Mathematically, for an individual series, it is measured as: M = Size of the N+12 th item 3. Mode - The mode is the observation or value that repeats itself the maximum number of times or that has the maximum frequency. It is easily measured by merely looking and locating the value with the highest frequency. 4. Quartiles - Quartiles are the values of the given set of data that divide the whole data or the set of observations into four equal segments. Q1=N+14th observationQ2=2N+ 14th observationQ3=3N+14th observation Here, N is the total number of items. 5. Deciles - Deciles are
the values of the given set of data that divide the whole data into 10 equal groups. There are 9 deciles in a set of data that divide the set of observations into 10 parts of the same size, namely D1D2D3D4D5D6D7D
8D9. D2=2 N+110th item D3=3N+110th item D4=4N+110th item D5=5N+110 th item D6=6N+110th item D7= 7N+110th item D8=8N+110th ite m D9=9N+110th item Here, N is the total number of items. 6. Percentile - A percentile divides the given set of data into 100 equal parts. There are a total of 99
percentiles that help in dividing the data into 100 parts by giving 99 dividing points, namely P1P2P3.............P99. P2=2N+1100th it em P3=3N+1100th item 7. Range - The range is defined as the span of distribution. It is calculated by finding the difference between the smallest and largest values of the given set of distribution. Page No 103:Question 2(B):Give reasons. 1) Arithmetic mean is measure of central tendency. 2) Mode is that value which has maximum frequency. 3) Mode has a number of merits. 4) Median divides the series into two equal parts. 5) Mean has not any limitations. 6) Median is not affected by remote values. 7) Percentiles divide the data into hundred equal parts. Answer:1. The central value represents the entire data in the sense that the values of observations in the data lie close to the central value. Arithmetic mean is the average of all items in the series. It is based on all the items in the data. Thus, it can be interpreted as a value that is an indicative of the various items in the data. Hence, we can say that arithmetic mean is a measure of the central tendency. 2. The mode is the observation or value that repeats itself the maximum number of times in the given series. Here, the frequency represents the number of times the value is repeated. Thus, it is correct to say that the mode is the observation or value that has the maximum frequency. Example: The following marks are scored by 10 students in a class. Find the modal marks.
A close examination of the data reveals that 15 occurs the highest number of times in the series i.e. 4 times. Thus, 15 is the modal marks. 3. Any observation that repeats itself the maximum number of times is called the mode of that data. The following are some of the merits of mode: 4. The median is the middlemost value of a set of data when it is arranged in an array (ascending or descending). Half of the items lie after the median and half of the items lie before the median; thus, the median divides the entire series into two equal parts. 5. The mean has both merits and
demerits. The following are a few limitations of the mean: 6. The median is the middlemost value of a set of data when it is arranged in an array (ascending or descending). It is just a positional average that is based on the number of observations in the series and not on the values of those observations. In other words, it is the number of observations and not the values of the observations that affect the median. Thus, we can say that the median does not get affected by the remote values. 7. A percentile divides the given set of data into 100 equal parts. There are a total of 99 percentiles that divide the data into 100 parts, giving 99 dividing points. Each group contains an equal number of observations, thus giving 100 groups of equal size. Thus, we can say that percentiles break data into 100 equal parts. Page No 103:Question 3(A):Distinguish between 1) Arithmetic mean and Mode Answer:1.
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Page No 103:Question 3(B):Write short notes 1) Merits and demerits of mode. 2) Write merits and demerits of median. 3) Define quartile- Give the formula for computing (1) Q1, (2) Q2, (3) Q3 4) Define deciles. Give the formulas for computing (1) D5, (ii) D7 (iii) D9 5) Define percentiles. Give the formulas. For computing the 3rd percentiles and 99th percentiles. 6) Give definitions (1) Median (2) Mode Answer:1. The following are the merits and demerits of the mode: Merits: i. It is easy to calculate. Demerits: i. The value of mode is ambiguous and indefinite in the sense that a series can even have two modes. 2. The following are the merits and demerits of the median: Merits: i. It is easy and simple to calculate. Demerits: i. It is not based on all observations. 3. Quartiles are the values of a given set of data that divide the whole data or set of observations into four equal parts. The following are the formulas for computing the three quartiles: Q1= N+14th observation Q2=2N+14th observation Q3=3N+14th observation 4. Deciles are the values of a given set of data that divide the whole data or set of observations into 10 equal parts. There are 9 deciles in data that divide it into 10 parts of the same size, namely D1D2D3D4D5D6D7
D8D9. D5=5N+110th item D7=7N+110th item D9=9N+19th item 5. Percentiles are the values of a given set of data that divide the whole set of observations into 100 equal parts. There are 99 percentiles that give 99 dividing points denoted by P1P2P3...........
P99. P3=3N+1100th itemP99= 99N+1100th item 6. (1) The median is the middlemost value of a given set of data arranged in an array (ascending or descending). It divides the data into two equal groups. Mathematically, for an individual series, it is calculated as: (2) The mode is the observation or value that repeats itself the maximum number of times or that has the maximum frequency. It is easily measured by merely looking and locating the value with the highest frequency. Page No 103:Question 4.1:Write answers for the following questions Explain the concept of central tendency. Answer:Central tendency refers to a central value or a representative value of a statistical series. The central value represents the entire data in the sense that the values of observations in the data lie close to the central value. Thus, central value can be said to represent the entire data set. A central value makes the raw data easy to understand and analyse, thereby draw clearer conclusions. Page No 103:Question 4.2:Write answers for the following questions Define arithmetic mean-state the merits and demerits of the mean. Answer:The arithmetic mean refers to the value calculated by dividing the sum of the values of the given items by the total number of items in a series. Mathematically, X=x1+x2+x3+......+xnN i. Simple to calculate: The arithmetic
mean is simple and easy to calculate, as it is measured using a simple formula. Demerits: i. Absurd results: It is often seen that the mean gives absurd or unreliable results, which are unrealistic in nature. Page No 103:Question 4.3:Write answers for the following questions Write the drawbacks of the median. Answer:The following are some drawbacks of the median: i. Not based on all observations: The median being the middlemost value is not based on all observations. It is said to be a positional average and hence is not dependent on all values. Page No 103:Question 4.4:Write answers for the following questions Write merits and demerits of range. Answer:The range is defined as the difference between the smallest and largest values of a given set of distribution. The following are the merits and demerits of the range: Merits Demerits Page No 103:Question 5.1:Do you agree or disagree with the following statements? Give Reasons. Median is the value of the most frequent item in the series. Answer:Disagree We do not agree with the statement. The median is the middlemost value of a given set of data arranged in an array (ascending or descending). It is the mode that depicts the most frequent item in a series. Page No 104:Question 5.2:Do you agree or disagree with the following statements? Give Reasons. Mean is the middle item of the series. Answer:Agree The statement is wrong. The arithmetic mean is the value calculated by dividing the sum of the values of the given items in a series by the total number of items in the series. The median, on the other hand, depicts the middle item of the given series. Page No 104:Question 5.3:Do you agree or disagree with the following statements? Give Reasons. Mean is a measure of central tendency. Answer:Agree We agree with the given statement. The mean is the value calculated by dividing the sum of the values of the given items in a series by the total number of items in the series. It is one of the measures of central tendency and is a representative of the whole set of data. Page No 104:Question 5.4:Do you agree or disagree with the following statements? Give Reasons. Mode is not the value of an item which occurs most frequently in a series. Answer:Disagree No, we do not agree with this statement. The mode is the value of an item that has the maximum frequency in a series or that occurs most frequently in a series. Page No 104:Question 5.5:Mean and mode means the same thing. Answer:Disagree No, we disagree with the statement. The mean is the value obtained by dividing the sum of the values of the given items in a series by the total number of items in the series. Mode, on the other hand, refers to the value that repeats itself the maximum number of times or that has the maximum frequency. Page No 104:Question 5.6:Do you agree or disagree with the following statements? Give Reasons. There is no difference between quartile, decile and percentile. Answer:Disagree No, we completely disagree with the statement. This is because the three concepts are very different from each other. Quartiles are the values of a given set of data that divide the whole data or observations into 4 equal parts. Deciles divide the given set of data into 10 equal groups. Percentiles are the values that divide the whole set of data into 100 equal parts. The numbers of quartiles, deciles and percentiles are 3, 9 and 99, respectively. Page No 104:Question 6.1:Answer the following questions in detail− The following are the monthly income of 10 families in a village. Calculate mean average income per family. Answer:Mean=X=ΣxnX=550+650+700+400+550 +650+800+900+450+35010=600010=600 Thus, mean income is Rs 600. Page No 104:Question 6.2:Answer the following questions in detail− Calculate the arithmetic mean from the following
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X=∑xifi∑fi=35450=7.08 Page No 104:Question 6.3:Answer the following questions in detail− In the following data the daily wages is given (in rupees) of 25 workers in a sugar factory. Calculate the mean wages
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X=∑xifi∑fi=178025=71.2 Page No 104:Question 6.4:Answer the following questions in detail− Calculate the arithmetic mean from the following data using direct method
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X=∑xifi∑fi=288090=320 Page No 104:Question 6.5:Answer the following questions in detail− Calculate mean from the following data by step deviation method.
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X=A+∑fdiN×i =35+120×10 =35.5 Page No 104:Question 6.6:Answer the following questions in detail− Calculate Arithmetic mean From the following data Use short-cut method
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X=A+∑fdN =35-110150 = 34.26 Page No 104:Question 6.7:Answer the following questions in detail− Find median from the following data
Answer:35, 35, 36, 37, 38, 39, 40 N = 7 Median=N+12th term =82=4th term =37 Thus, the median is the 4th item, i.e., 37. Page No 104:Question 6.8:Answer the following questions in detail− Find median marks obtained by the students out of 50 marks in economics.
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Median=N2th term = 482=24th item As 24 falls in the cumulative frequency of 31, the median is the value corresponding to the 31st C.F. Page No 104:Question 6.9:Answer the following questions in detail− Calculate median from the following data-
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Median can be calculated using the following formula: N2th item=402=20th item 20th item falls in the 27th C.F Median=L1+L2-L1f1×N2-C.F L1= 30 =30+40-3010×402-17=30+3=33 Page No 104:Question 6.10:Answer the following questions in detail− Find the mode from the following data.
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The mode is the value having the highest frequency. Here, the mode is 10, as it has the highest frequency of 4. Page No 104:Question 6.11:Answer the following questions in detail− Calculate the mode from the following data
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The mode is the value having the highest frequency. Here, the mode is 73, as it has the highest frequency of 160. Page No 104:Question 6.12:Answer the following questions in detail− Calculate the mode from the following fequency distribution
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In the given series, (8–12) is the modal class, as it has the highest frequency of 12. Mode=L1+L2-L1 f1- f02 f1-f0-f2 =8+12-8 12-62×12-6-7 =8+2411=5.82 Page No 104:Question 6.13:
Answer the following questions in detail− Calculate range from the following data
Answer:100, 150, 200, 300, 550, 600 Page No 104:Question 6.14:Answer the following questions in detail− Wage distribution of 100 workers is given below. Calculate range.
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Range=Highest value - Lowest value =50-10 =40 Page No 104:Question 6.15:Answer the following questions in detail− From the following data of pocket money given to the students, calculate Q1, Q2 and Q3 50, 40, 60, 90, 80, 70, 100, 140, 130, 120, 110 Answer:First the given data is arranged in ascending order as follows: 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 The three quartiles can be calculated in the following manner: N=11Q1=N+
14th observation =11+14th 3rd observationQ1=60 Page No 104:Question 6.16:Answer the following questions in detail− Calculate Q1 and Q3 from the following data.
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Q1=N4th=1504th=57.5th It falls in the 50th c.f Now, Q1=30-40Q1=L1+L2-L1fN4-cfQ1 =30+40-30251504-25 Thus, we have: Q1=35Q3=3N4 th =3×1504th=112.5 This falls in the 125th c.f Q3=50-60Q3=L1+L2-L1f3N4-cfQ3=50+60 -50353×1504-90 Thus, we have: Page No 104:Question 6.17:Answer the following questions in detail− From the following frequency distribution calculate first and third quartile.
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The quartiles can be found using the following formulas: Q1=N+14th item =59+ 14=15th It falls in the 23rd c.f which corresponds to item having value 6. Thus, Q1 = 6 Q3=3N+14th item=3 ×59+14=45th item. It falls in the 45th c.f which corresponds to item having value 10. Thus, Q3 = 10 Page No 105:Question 6.18:Answer the following questions in detail− From the following data calculate D1, D4 and D7 11, 15, 12, 16, 13, 17, 14, 18, 20, 19, 25. Answer:The given data is first arranged in ascending order as follows: N=19D1=N+110th item =19+110=2nd item Thus, D1=12 D4=4N+110th item =8th Thus, D4=18 D7=7N+110th item =14th itemThus, D7=24 Page No 105:Question 6.19:Answer the following questions in detail− From the following data find out D2, D7 and D9
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D2=2N10th=16010=16th item 16th item falls in 27th c.f D2=20+30-201416010-13=22.14D7=7N 10th=56010th=56th item 56th item falls in 70th C.F. D7=40+50-4018× 56010-52 =42.22D9=9N10th=720 10th =72nd item 72nd item falls in 76th C.F. D9=50+60-506×72010-70 =53.33 Page No 105:Question 6.20:Answer the following questions in detail− Find D3 and D4 from the following data.
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D3=3N+110th item =345+110 =13.8th item 13.8th item falls in 5th C.F which corresponds to X equal to 1 Thus, D3 = 1 D4=4+N+110 th item =445+110th=18.4th item 18.4th item falls in 20th C.F. which corresponds to X equal to 4 Thus, D4 = 4 Page No 105:Question 6.21:Answer the following questions in detail− Calculate P40 and P70 for the following data.
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P40=40N100th item =40×25100th item =10th items 10th item falls in 10th C.F. P40=L1+L2
-L1f40N100-c.fP40=L1+L2-L14
40N100-c.f 17.5th item falls in 21st C.F. P70=40+50 -4061750100-215 =44.16 View NCERT Solutions for all chapters of Class 13 Which of the measure of central tendency does divide the distribution in two equal parts?The median is the middle value in distribution when the values are arranged in ascending or descending order. The median divides the distribution in half (there are 50% of observations on either side of the median value).
Which measure of central tendency divides a frequency distribution into four equal parts?Quartiles divide a rank-ordered data set into four equal parts. The values that divide each part are called the first, second, and third quartiles; and they are denoted by Q1, Q2, and Q3, respectively. Q1 is the "middle" value in the first half of the rank-ordered data set.
Which divides data into two equal parts?Certain quantiles are particularly important: The median of a data set divides the data into two equal parts: the bottom 50% and the top 50%. Quartiles divide the data four equal parts and percentiles divide it into hundredths, or 100 equal parts.
Which measure of central tendency will be equal for a symmetrical distribution?Of the three measures of tendency, the mean is most heavily influenced by any outliers or skewness. In a symmetrical distribution, the mean, median, and mode are all equal. In these cases, the mean is often the preferred measure of central tendency.
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