Imagine that you're standing in a large room when a loud noise is made. you begin hearing a series of echoes. which characteristic of sound best explains what just happened?

An insurance company wants to know if the average speed at which men drive cars is higher than that of women drivers. the company took a random sample of 27 cars driven by men on a highway and found the mean speed to be 72 miles per hour with a standard deviation of 2.2 miles per hour. another sample of 18 cars driven by women on the same highway gave a mean speed of 68 miles per hour with a standard deviation of 2.5 miles per hour. assume that the speeds at which all men and all women drive cars on this highway are both approximately normally distributed with unknown and unequal population standard deviations.

What are two different ways you could find the value of a? explain these methods.

In science and physics what is the standard unit of measure for speed?