When Natalie runs the 400 meter dash, her finishing times are normally distributed with a mean of 71 seconds and a standard deviation of 2.5 seconds. What percentage of races will her finishing time be between 71 and 77 seconds, to the nearest tenth?

49.2%

Step-by-step explanation:

1.4285 inches/hour

Step-by-step explanation: 1/5 of an hour is equal to 20%, or 0.2 hours. 2/7 inch is equal to 0.2857 inches, approximately. If she sews 0,2857 inches in 0,2 hours, we can cross multiply the values we want to discover:

x inches  -  1 hour

0.2857 inches - 0.2 hours

Then, 1.4285 inches are sewed in one hour.