Based on the calculations, the value of the test statistic and p-value are equal to -2.1213 and 0.0169 respectively.
<u>Given the following data:</u>
<h3>How to compute the test static?</h3>
Mathematically, the value of the test statistic can be computed by using this formula:
zₓ = -2.1213.
From the z-table, the p-value is given by:
P(Z < zₓ) = P(Z < -2.1213)
P(Z < -2.1213) = 0.0169.
Since the p-value is equal to 0.0169 less than α = 0.05, we would reject H₀ : µ equal to 20. Thus, we would conclude that µ < 20.
Read more on standard deviation here: brainly.com/question/4302527