Suppose Matt wants to test the claim that the mean pulse rate of adult males is equal to 69 bpm, since he expects it to be lower. A random sample of 140 adult males is used and found to have a mean of 68.3 bpm and a standard deviation of 10.7 bpm. Find the value of the test statistic.

z (s) = - 0.7740

Step-by-step explanation:

Normal Distribution

sample size n = 140

sample mean 68.3

A ne tailed-test to the left from problem statement

1.-Test hypothesis

H₀ null hypothesis μ₀ = 69

Hₐ alternative hypothesis μ₀ < 69

2. - To find a value of test statistics z (s)

z (s) = [ (μ - μ₀) / (σ / √n)

z (s) = (68.3 - 69) / (10.7/√140) ⇒ z (s) = - 0.7*11.83 / 10.7

z (s) = - 0.7740