Question

Hi am having a little problem with a maths question I found the mean but I can’t figure out the rest.

Answer 1

-0.201

5) To find out the Z-score, we need the mean and the value from this list:

10,20,35, 44,55,64, 75,81, 87, 99

11, 22, 36, 48, 56, 68, 76, 82, 89, 101

13, 23, 38, 49, 57, 69, 76, 83, 90, 102,

15, 23, 41, 50, 60, 70, 78, 83, 94, 105,

18, 30, 44, 50, 63, 73, 80, 85, 96, 107

5.2) Let's calculate the mean:

`x=(2284)/(48)=475.5`

Note that this can be found by adding all those data points, and then dividing them by the number of data points.

We also need the standard deviation:

`\begin{gathered} \sigma={\sqrt[]{\frac{\sum(x_i-{\mu})^2}{N-1}}} \\ \sigma=2009.81501\approx2009.82 \end{gathered}`

The Standard Deviation is found by the square root of the sum of the square subtraction from the mean and each data point.

5.3) So finally, we can find out the Z score by using this formula:

`\begin{gathered} z=(x-\mu)/(\sigma) \\ z=(70-475.5)/(2009.82) \\ z=-0.20175 \end{gathered}`

And that is the answer