What is the probability that a randomly selected teacher makes less than $53,000 per year?

Question

The average teachers' salary in a certain state is $57,337

. Suppose that the distribution of salaries is normal with a standard deviation of $7500

. Assume that the sample is taken from a large population and the correction factor can be ignored. Use a TI-83 Plus/TI-84 Plus calculator and round the answer to at least four decimal places.

Answer 1

Using TI-84:

Click 2nd VARS which is DISTR

Pick 2 in menu: normal CDF

The lower will be -1E99 default (If it isn't input that)

The upper is z = (57337 - 53000)/7500 (put in value, not equation)

Leave the mu and sigma alone

go to paste hit enter

hit enter again

result is your fractional probability

You can also put the x value 57337 for upper, 53000 for mu, and 7500 for sigma if you don't want to use normalized distribution and z statistic.

Please consider a tutor. Take care.