9. Stan’s Deli is situated inside a large industrial park. The weekday gross sales at Stan’s average $1,240, with a standard deviation of $180. Find the probability that the average over the next 40 weekdays will exceed $1,200. Please note the assumptions that are used in making the calculation.

Answer:0.9792Step-by-step explanation:Data provided in the question:Average gross sales = $1,240Standard deviation = $180sample size = 40Now,standard deviation of sample average = [tex]\frac{\textup{Standard deviation}}{\sqrt{n}}[/tex] = [tex]\frac{180}{\sqrt{40}}[/tex] = 28.46 Now,z value for 1200 = [tex]\frac{(1200-1240)}{28.46}[/tex] = -1.4, and, p value for (z = -1.4) = 0.0808 therefore,P(average < $1200) = 0.0808 Thus,probability that the average over the next 40 weekdays will exceed $1,200= 1 - 0.808 = 0.9792