A town's january high temperatures average 36degreesf with a standard deviation of 8degrees, while in july the mean high temperature is 72degrees and the standard deviation is 9degrees. in which month is it more unusual to have a day with a high temperature of 57degrees? explain.

July

Step-by-step explanation:

Formula of z score :

Given: The mean high temperature in January =

Standard deviation :

For X =

The mean high temperature in July =

Standard deviation :

⇒ 57° F is about 2.6 standard deviations above the mean of January high temperatures, and  57° F is about 1.9 standard deviations below the mean of July’s high temperatures.

A general rule says that z-scores lower than -1.96 or higher than 1.96 are considered unusual .

Hence, the 57˚F is  more unusual in January.