Question

The present study shows data for direct flights from Orlando to Miami for one airline. The airline claims that the flying time (time in the air) of direct flights from Orlando to Miami takes 45 minutes. The company would like to test the claim and collects a random sample of 90 flights. We will find the average and standard deviation for the flights’ times for the random sample of flights. We will use Excel functions to find the critical value(s) that define(s) the rejection region. We will use formulas to find the test statistic, compare it with our critical value(s), and decide if we should reject or not reject the null hypothesis. We will use different alpha levels to test the hypothesis. We will find the observed level of significance and use it to make conclusions about the claim. We will identify possible errors made and their types. Assume that the distribution of the flight times is normal and the sample is randomly selected.

Flight Duration (Time in the air) in minutes
45.0
42.0
41.0
38.0
41.0
44.0
51.0
47.0
43.0
40.0
46.0
45.0
43.0
44.0
43.0
39.0
44.0
48.0
48.0
51.0
50.0
43.0
41.0
51.0
40.0
45.0
49.0
55.0
41.0
41.0
40.0
41.0
45.0
50.0
47.0
50.0
42.0
46.0
48.0
44.0
42.0
47.0
46.0
48.0
48.0
51.0
48.0
59.0
46.0
47.0
52.0
49.0
50.0
50.0
52.0
49.0
42.0
42.0
43.0
45.0
39.0
49.0
48.0
49.0
43.0
41.0
45.0
43.0
43.0
50.0
42.0
46.0
41.0
47.0
43.0
51.0
48.0
47.0
43.0
50.0
44.0
42.0
56.0
49.0
46.0
44.0
48.0
51.0
51.0
49.0

1) find the Standard Deviation of the flight time for the sample flights

2) find the sample size of the sample of flights

3) to test the null hypothesis for the mean flight time, what is the appropriate probably table to use?

4) identify the degrees of freedom needed to find the critical values?

5) the company would like to test the claim (null hypothesis) that the flight takes 45 minutes against the alternative that it does not. is this a two sided test?

6) find the value of the test statistic

7) find a one-sided critical value from the appropriate probability table to test the claim at alpha = 0.05

8) What is/are the sign(s) of the critical value(s) for the test of the hypothesis at alpha=0.05?

9) By assessing the answers above, do you reject the null hypothesis? why?

Show formula if possible. Thank you

Answer 1

Given 90 sample values are entered in column B. Formulae are given just for ur referece.