Question

find mean of the following data class interval
20-60. 7
60-100. 5
100-150. 16
150-250. 12
250-350. 2
350-450. 3

Answer 1

Heya,

Kindly refer the above attachment for the answer

Hope it helps :)

Regards,
Shobana

Answer 2

Hey there!!
Down here⏬

>> Find the midpoint

• 20-60. 7
Here, midpoint of class interval is 20 (60-20/2)

• 60-100. 5
Here, midpoint of class interval is 20 (100-60/2)

• 100-150. 16
Here, midpoint of class interval is 25 (150-100/2)

• 150-250. 12
Here, midpoint of class interval is 50
(250-150/2)

• 250-350. 2
Here, the midpoint of class interval is 50
(350-250/2)

• 350-450. 3
Here, the midpoint of class interval is 50 (450-350/2)

>> Multiply the midpoint by frequency.

• For 20-60, (20)(7) = 140

• For 60-100, (20)(5) = 100

• For 100-150 = (25)(16) = 400

• For 150-250 = (50)(12) = 600

• For 250-350 = (50)(2) = 100

• For 350-450 = (50)(2) = 100

>> Add results

• 140+100+400+600+100+100 = 1440

>> Sum of frequencies


• 7+5+16+12+2+3 = 45

>> Mean of grouped data = Sum of (interval×Frequency) / sum of frequency)

• 1440/45 = 32

>> Therefore, 32 is the mean of the grouped data.

Hope it help you. ☺