Question

Destiny performs a hypothesis test on a population with µ = 115 and σ = 30. Her sample size is 25 with a mean of 120.4. Which of the following correctly depicts the z-statistic for this data?
a)0.04
b)0.90
c)3.52
d)3.93

Answer 1

z statistic or z score can be calculated using the following formula:

z = (x – u) / (σ / sqrt n)

So simply substitute the given values:

z = (120.4 – 115) / (30 / sqrt 25)

z = 0.90

 

Answer:

b. 0.90

Answer 2

The answer is B) 0.90