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Chapter 2: Q.113 (page 156)

Twenty-five randomly selected students were asked the number of movies they watched the previous week. The results are as follows:

a. Find the sample mean x¯.

b. Find the approximate sample standard deviation, s.

Short Answer

Expert verified

(a) The sample mean is =1.48.

(b) The standard deviation is =1.122497.

Step by step solution

01

(a) Mean : 

The total of all observation or data point values divided by the number of observations.

02

(a) Explanation : 

Sample mean x¯=∑fx∑f=3725=1.48.

Hence, the sample mean is1.48.

03

(b) Standard deviation :

The standard deviation is a measure that indicates how much variation (such as spread, dispersion, and spread) is there from the mean.

04

(b) Explanation : 

Sample size =n

Sample variation s2=∑fx-x¯2n-1=30.2424=1.26.

Sample standard deviation s=1.26=1.122497.

Hence, the standard deviation is1.122497.

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