Assume that all variable are approximately normally distributed.

State Gasoline TaxesA random sample of state gasoline taxes (in cents) is shown here for 12 states. Use the data to estimate the true population mean gasoline tax with 90% confidence. Does your interval contain the national average of 44.7 cents?

38.4 |
40.9 |
67 |
32.5 |
51.5 |
43.4 |

38 |
43.4 |
50.7 |
35.4 |
39.3 |
41.4 |

Source http://www.api org statistics/fueltaxes/

Answer

Step 1 of 1</p>

(a)

We have a random sample of state gasoline taxes (in cents) is shown here for 12 states.

We are asked to find the estimate the true population mean gasoline tax with 90% confidence.

Does your interval contain the national average of 44.7 cents?

38.4 | 40.9 | 67 | 32.5 | 51.5 | 43.4 |

38 | 43.4 | 50.7 | 35.4 | 39.3 | 41.4 |

We have given

First, we will find the sample mean and sample standard deviation.

We need to find the confidence interval for the mean and is...