Question

The data set below provides the number of DVD movies owned by 7 students,75,78,81,90,95, 97,100Suppose that the number 75 from this data set changed to 82,What is the mean before the change? After the change?What is the median before the change? After the change?Chance

Answer 1

Given:

75,78,81,90,95, 97,100

Mean before the change.

Mean =

`\begin{gathered} \text{Mean}=(\Sigma X)/(n) \\ \\ =(75+78+81+90+95+97+100)/(7) \\ \\ =(616)/(7) \\ \\ =88 \end{gathered}`

Hence, mean before the change = 88

Mean after the change

82,78,81,90,95, 97,100

`\begin{gathered} \text{Mean}=(82+78+81+90+95+97+100)/(7) \\ \\ =(623)/(7) \\ \\ =89 \end{gathered}`

Hence, mean after the change = 89

Median before the change.

To find the median, re-arrange the numbers in ascending order and pick the middle number.

That is;

75, 78 ,81, 90, 95, 97,100

The middle number is 90

Hence, median before the change = 90

Median after the change

82,78,81,90,95, 97,100

Re-arrange from lowest to highest.

78, 81,82, 90, 95, 97, 100

The middle number is 90.

Hence, the median after the change is 90.