SOLUTION: During September, the average temperature of Laurel Lake is 64.2� and the standard deviation is 3.2�. Assume the variable is normally distributed. For a randomly selected day, fi

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Question 726730: During September, the average temperature of Laurel Lake is 64.2� and the standard deviation is 3.2�. Assume the variable is normally distributed. For a randomly selected day, find the probability that the temperature will be
a. Above 62�
b. Below 67�
c. Between 65� and 68�
My answers
a. -.6875
b. .875
c. .25 and 1.1875
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!
Notes:

1) The probability of any event is ALWAYS POSITIVE (unless the probability is 0) and it is ALWAYS LESS THAN 1. So if p is the probability of some event, then (where p is a real number between 0 and 1)

2) You can't have two values for the probability in part c). Only one probability is possible.

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Use either a calculator or a table to get the following answers

a) 0.754116149619739

b) 0.809213047147489

c) 0.283778446023862

Make sure you round to the proper decimal place as instructed.

Note: if you need me to show you how to use a calculator to get that, let me know. Thanks.

If you don't have a calculator and you don't want to use a table, then wolfram alpha is your next best bet. Just go to that site, type in "normalcdf" without quotes, and you'll be able to compute the probabilities.