Question

Exercise 11 Your Saturn 3-door was a great car. The owner's manual said that it had a 10-gallon gas tank.You kept track of the number of gallons of gas needed

to fill up the tank once the "Low Fuel"icon lit up on the dashboard. Here are the results of 20 random fill-ups (in gallons): (a) Let X represent the number of gallons of gas needed to fill your car's gas tank. In order to use the formula from the lesson to construct a confidence interval for the true mean number of gallons of gas u to fill your gas tank, we have to assume that X is normally distributed. Why is this a reasonable assumption based on the box plot and histogram? Please note that this question is asking about the shape of X and not X. (b) The sample mean i for the gas fill-up data is: Construct and evaluate a two-sided 95% confidence interval for µ. The population standard deviation is o =0.09 gallons. (c) Using the same data set to construct a 99% confidence interval for u, the width of the interval: A. Increases B. Decreases C. Is not affected D. Not enough information

Fig: 1

Fig: 2

Fig: 3

Fig: 4

Fig: 5

Fig: 6

Fig: 7

Fig: 8

Fig: 9

Fig: 10