Question

.

A students received a score of 50 on his history test. The test had a mean of 69 and a standard deviation of 10. Find the z score and assess whether his score is considered unusual.

1.90; unusual

–1.90; not unusual

–1.90; unusual

1.90; not unusual

Answer 1

Answer: The Z-score = - 1.90 unusual

Explanation:

Answer 2

c) The Z-score = - 1.90 unusual

Explanation:

Explanation:-

Let 'X' be the random variable in normal distribution

Given student received a score X = 50

Mean of the Population x⁻ = 69

standard deviation of the Population 'σ' = 10

now

`Z = (x^(-)-mean )/(S.D)`

`Z = (x^(-)-mean )/(S.D) = (50 -69)/(10) = - 1.90`

The Z-score = - 1.90

Conclusion:-

The Z-score = - 1.90 unusual