Table A-6 will be shown below for reference. Since none of the answer choices contain the critical value for 61, we can just round that number to 60. We will see that the critical value is 0.254. If you're having trouble reading the table below, look at the columns to find the corresponding significance level you are working with then find the sample value.
If a plane flies an average of 325 miles per hour, to find out 7 hours you will need to times 325 by 7. 325 x 7 = 2275. therefore the flight for 7 hours was 2275 miles.