Easy 644 likes
Share

Question

The age of 100 persons present in a workshop is given in the following table. Find the average age of 100 people (by any method):

Age Group Number of People
10 – 20 8
20 – 30 12
30 – 40 20
40 – 50 22
50 – 60 18
60 – 70 20
WBBSE Class X Mathematics Statistics 04 Mark 2025

Answer

Age Group Number of People (f) Midpoint (x) fx
10 – 20 8 15 120
20 – 30 12 25 300
30 – 40 20 35 700
40 – 50 22 45 990
50 – 60 18 55 990
60 – 70 20 65 1300


Σ fx = 120 + 300 + 700 + 990 + 990 + 1300

= 4400

Total number of people:

Σ f = 8 + 12 + 20 + 22 + 18 + 20

= 100

\bar{x} = \frac{4400}{100}

\bar{x} = 44

Related Questions

More WBBSE Easy level questions

1/12
Easy
714
Q. State True or False: Mode = 2 × Median – 3 × Mean.
A. False Explanation: The correct empirical relation is: Mode = 3 × Median...
View Question
Easy
687
Q. x is the mean of (p + q) numbe₹ If y be the mean of...
View Question
Easy
985
Q. Find the mean by any suitable method from the following frequency distribution table
A. Class Interval mid-point (x) Frequency (f) fx 85 - 105 95 3...
View Question
Easy
761
Q. Construct the table of cumulative frequency (greater than type) and draw the ogive from the...
A. Class Cummulative Frequency Greater than 0 100 Greater than 10 93 Greater...
View Question
Moderate
808
Q. Draw an ogive on the graph paper after calculating the cumulative frequency (less than type)...
A. Class Interval Frequency CF 0 - 10 1 1 10 - 20...
View Question
Moderate
637
Q. The median of following data is 32. Find the value of x and y if...
A. Class Interval Frequency (f) CF 0 - 10 10 10 10 -...
View Question
Easy
667
Q. The mean of a frequency distribution is 7 and Σfx = 140, then find the...
A. Mean = Σfx / Σf ⇒ 7 = 140 / Σf ⇒...
View Question
Easy
611
Q. State True or False: The average of n numbers is x̄. If the sum of...
A. False Explanation: Average of n numbers = x̄ ⇒ Total sum of...
View Question
Easy
984
Q. If A and M be the arithmetic mean and median of first ten natural numbers,...
A. (d) A = M Explanation: 10 Natural Number = 1, 2, 3,...
View Question
Easy
980
Q. If 6, 8, 10, 12, 13, x are in increasing order and their mean and...
A. Numbers in ascending order are 6, 8, 10, 12, 13, x Mean...
View Question
Easy
938
Q. State True or False: The Mode of the data 5, 2, 4, 3, 5, 2,...
A. False Explanation the mode is 2 as well as 5
View Question
Easy
749
Q. The median of the numbers 8, 15, 10, 11, 7, 9, 11, 13 and 16...
A. 11 Explanation 7, 8, 9, 10, 11, 11, 13, 15, 16 Here...
View Question