Question

According to an automobile association, the average cost of a gallon of regular unleaded fuel at gas stations in a certain month was $2 827. Assume that the standard deviation of such costs is $0 15. Suppose that a random sample of n100 gas stations is selected from the population and the month's cost per gallion of regular unleaded fuel is determined for each Considor & the sample mean cost per gallon. Complete part a through d Click the icon to view the table of normal curve areas a. Calculate μ, and ơi Do not include the $ symbol in your answer Round to three decimal places as needed) Do not include the S symbol in your answer Round to three decimal places as needed.) b. What is the approximate probability that the sample has a mean fuel cost between $2 84 and $2 86 P(2 84 sxs2.86)- Round to four decimal places as needed) c. What is the approximate probability that the sample has a mean fuel cost mat exceeds $2 855 P 2 855) (Round to four decimal places as needed ) d. How would the sampling distribution of x change if the sample size n were doubled fronท 100 to 2007 Choose the correct answer below. O A. μǐ doesnt change σǐ decreases by a factor of 2 Click to select your answers)

Answer 1

p0033 .013. O ONS 一0.1792 z 1-8666 Sqanned with mScanner

double Sample sfz 2. 179 2 2280 d) pl2.84S R2.G decrease Scanned with CamScanner