The population mean height of a basketball player is 200 cm

Question

1.      The population mean height of a basketball player is 200 cm with a standard deviation of 15 cm. In a sample of 40 basketball players, what is the probability of getting a sample mean height of 195 cm or more?

( )
a.
0.0174
( )
b.
0.3707
( )
c.
0.6293
( )
d.
0.9826
 

Answer 1

First we need to extract the relevant information

Mean = 200

SD = 15

N = 40

We also need to standardize this as it is sample means and to do that we need to find a z-score.

Formula : raw score - mean/standard deviation

In this instance, the "raw score" is 195

(195-200)/15 = -.33

Look at a z-table, and you will see the corresponding percent is .3707.

However, because the question asks what is the probability of getting a sample mean height GREATER than 195, we need to subtract .3707 from 1 to get .6293.

If the question were to ask what is the probability of getting a sample mean height LOWER than 195, then we could use .3707.

Answer : .6293