# Explanation needed to the quiz question

. Johnny wanted to know how many days per week people in his class exercise, so he asked 3 of his friends. The answers he got were 1, 3 and 5. Based on this, which of the following is true about the results Johnny found? (Hint: Do the numbers [1,3,5] represent a population or a sample?)

3 , 2

Johnny wanted to know how many days per week people in his class exercise, so he asked 3 of his friends

-class = population and 3 friends = simple

The answers he got were 1, 3 and 5.

so you have (1,3,5)

mean = 1+3+5 / 3 = 3 *you are working with simple so mean = x̄

variance = 8

standard deviation = 2 *you are working with simple so standard deviation= s

as here the value of mean is 3 from the formula of variance =4 when dividing by (n-1) [* As this is a sample]

hence , standard deviation= 2

μ represents the population mean.

σ represents the population standard deviation.

xˉ represents the sample mean.

s represents the sample standard deviation.

Given Johnny's sample:

Sample mean xˉ=1+3+5/3=9/3=3

Sample standard deviation s=√(1−3)^2+(3−3)^2+(5−3)^2/3−1=

√4+0+4/2=√8/2=√4

=2

so xˉ=3, s=2