statistics

. Mean of 20 observations is 17. If in the observations, observation 40 is replaced by 12, find the new mean

• 15.6

• 15.5

• 17

• 18

Mean of 36 observations is 12. One observation 47 was misread as 74. Find the correct mean

Answer.

• 11.20

• 11.25

• 15

• 16

Tags

CCSS.HSS.ID.A.3

Determine the mean of first 10 natural numbers.

• 5.5

• 5.6

• 10.5

• 11.5

Tags

CCSS.HSS.ID.A.2

CCSS.HSS.MD.A.2

Write the class mark of an interval 90 – 120.

• 105

• 110

• 95

• 100

There are 50 numbers. Each number is subtracted from 53 and the mean of the numbers so obtained is found to be – 3.5. Find the mean of the given numbers.

• 55.5

• 55.9

• 56.5

• 55

Tags

CCSS.HSA.CED.A.1

If the median of data (arranged in ascending order) 31, 33, 35, x, x+10, 48, 48, 50 is 40, then find value of x.

• 40

• 35

• 50

• 60

Tags

CCSS.HSA.CED.A.1

CCSS.HSA.REI.B.3

To draw a histogram to represent the following frequency distribution :



Find the adjusted frequency for the class 25-45.

• 2

• 5

• 8

• 15

Tags

CCSS.HSS.ID.A.1

Find the mean of the following distribution

• 20

• 19

• 28

• 45

Tags

CCSS.HSS.ID.A.2

CCSS.HSS.MD.A.2

The scores of an English test out of 100 of 20 students are given below :

75, 69, 88, 55, 95, 88, 73, 64, 75, 98, 88, 95, 90, 95, 88, 44, 59, 67, 88, 99.

Find the median

• 90

• 88

• 95

• 100

A teacher wanted to analyse the performance of two sections of students in a mathematics test of 100 marks. Looking at their performances, she found that a few students got under 20 marks and a few got 70 marks or above. So she decided to group them into intervals of varying sizes as follows

0 – 20, 20 – 30, …, 60 – 70, 70 – 100. Then she formed the following table

Find the probability that a student obtained less than 20% in the mathematics test

• 7/90

• 20/90

• 15/90

• 1/90