Question

Teachers' Salaries The average annual salary for all U.S. teachers is $47,750. Assume that the distribution is normal and the standard deviation is $5680Find the probabilities.P (X>45,500)

Answer 1

`\begin{gathered} \mu=47,750 \\ \sigma=5,680 \\ X>45,500 \\ Z=(X-\mu)/(\sigma) \\ Z=(45,500-47,750)/(5,680) \\ Z=(-2,250)/(5,680) \\ Z=-0.3961 \\ P(X>45,500)\text{ using chart for z} \\ P(X>45,500)\text{ =}0.654=65.4\text{ \%} \\ \text{The }probability\text{ }is\text{ }0.654\text{ or }65.4\text{ \%} \end{gathered}`