Question

HELP PLEASE!!! The readings on the thermometers are normally distributed with a mean of

0° and a standard deviation of 1º. The value of PIX greater than - 1.96) is
A. 0.9750 B. 0.9970 C. 0.9950 D. 0.9850

Answer 1

Answer: A. 0.9750

Step-by-step explanation:

You can use a calculator or a Z table here. I'll go with the table option.

Using a Z table, you should find that P(Z < -1.96) = 0.0250

So the remaining area must be 1 - 0.0250 = 0.9750 which represents P(Z > -1.96). This is the same as P(X > -1.96) because X is distributed identical to the Z distribution (mean = 0, std dev = 1).

If you go the calculator route, then it depends on which calculator or computer software you use. If you prefer this route, then let me know which calculator you're using and I'll try to find the correct input to type in for that calculator.