Last answered:

08 Feb 2024

Posted on:

13 Nov 2022

1

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?)

4 answers ( 0 marked as helpful)
Posted on:

26 Jan 2023

0

3 , 2

Posted on:

06 Mar 2023

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


Posted on:

08 Jun 2023

2

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

Posted on:

08 Feb 2024

0

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

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