The 400-meter race times recorded in the boys track meet was normally distributed with a standard deviation of 3 seconds. if david finished the race in 51.2 seconds with a z-score of -2.6, what is the mean time?

Can't gugys answer the ratio question. this is urgent the plans of a building is drawn toward scale of 1: 1000. kfc the foyer on the plans measures 62mm by 54mm, how large is the foyer in real life?

The lengths of nails produced in a factory are normally distributed with a mean of 4.91 centimeters and a standard deviation of 0.05 centimeters. find the two lengths that separate the top 4% and the bottom 4%. these lengths could serve as limits used to identify which nails should be rejected. round your answer to the nearest hundredth, if necessary.

15/16 as a decimal rounded to the nearest hundredth