Female administrators. The average annual salary of 20 female hospital administrators is $80,900. These administrators believe they make less than their male counterparts because of sex bias. Published results suggest that hospital administrators have an average salary of

μ = $85,100 (σ = $10,000).

(a) What conditions (assumptions) are needed to perform a z-test to address this question?

(b) Sketch the sampling distribution of based on an SRS of n = 20.

Assume μ = $85,100 and σ = $10,000. Mark the horizontal axis with landmarks that are ±1 and ±2 standard errors around μ.

Locate = $80,900 on the horizontal axis of the curve.

(c) Calculate the zstat and P-value for an observed of $80,900.

(d) Come up with four explanations for the lower-than-expected observed sample mean.