Question

Adult racehorse weights are normally distributed, with a mean of 500 kg and a standard deviation of 33 kg. Approximately what percentage of the adult racehorses weigh more than 570 kg?

1.7%
98.3%
93.3%
0.12%

Answer 1

Since we know in a standard deviation that mean plus 1 SD is 533 (66%) and 2 SD is 566 (95%) and 570 is slightly more than 566. Then the amount of race horses weighing within 570 is 98.3%. So to find those more than the mean would be 100%-98.3% which is 1.7%