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

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.