Use the following information to answer questions 38–40.

A website about birds made the 4 claims below about American robins.

1. The population of American robins in 2015 was 320 million.

2. The wingspans of all American robins can be fit to a normal distribution model that has a mean of 36.00 cm and a standard deviation of 2.50 cm.

3. The maximum reported flight speed for an American robin is 3,168 feet per minute.

4. A certain conservation organization will only consider American robins threatened if the total number of American robins declines by at least 30% over a 10-year period.