Answer:
Step-by-step explanation:
As we know z- score is defined by the formula [tex]z=\frac{x-\mu }{\sigma }[/tex]
Mean of the scores is given as 78 and standard deviation 11.
Now for x = 60
[tex]z=\frac{x-\mu }{\sigma }[/tex]
[tex]z=\frac{60-78}{11}=\frac{(-18)}{11}=-1.64[/tex]
For x = 70
[tex]z=\frac{70-78}{11}[/tex]
[tex]z=\frac{(-8)}{11}[/tex] =-0.73
For x = 80
[tex]z=\frac{80-78}{11}[/tex]
z = 0.18
For x = 90
[tex]z=\frac{90-78}{11}[/tex]
z = 1.09
For x = 60
z = -1.64
For x = 65
[tex]z=\frac{65-78}{11}[/tex]
z = -1.18
For x = 70
z = -0.73
For x = 80
z = 0.18
For x = 99
[tex]z=\frac{99-78}{11}[/tex]
z = 1.91
For x = 89
[tex]z=\frac{89-78}{11}[/tex]
z = 1
For x = 75
[tex]z=\frac{75-78}{11}[/tex]
z = -0.27