In: Statistics and Probability
The height of women ages 20-29 are normally distributed, with a mean of 64.3 inches. Assume sigmaequals2.5 inches. Are you more likely to randomly select 1 woman with a height less than 66.2 inches or are you more likely to select a sample of 18 women with a mean height less than 66.2 inches? Explain. What is the probability of randomly selecting 1 woman with a height of less than 66.2 inches? _______(Round to four decimal places as needed.) What is the probability of selecting a sample of 18 women with a mean height less than 66.2 inches? _______ (Round to four decimal places as needed.)
Are you more likely to randomly select 1 woman with a height less than 66.2 inches or are you more likely to select a sample of 18 women with a mean height less than 66.2 inches? Choose the correct answer below.
A. It is more likely to select 1 woman with a height less than 66.2 inches because the probability is lower.
B. It is more likely to select a sample of 18 women with a mean height less than 66.2 inches because the sample of 18 has a lower probability.
C. It is more likely to select a sample of 18 women with a mean height less than 66.2 inches because the sample of 18 has a higher probability.
D. It is more likely to select 1 woman with a height less than 66.2 inches because the probability is higher.
Are you more likely to randomly select 1 woman with a height less than 66.2 inches or are you more likely to select a sample of 18 women with a mean height less than 66.2 inches? Choose the correct answer below.
Answer :- C. It is more likely to select a sample of 18 women with a mean height less than 66.2 inches because the sample of 18 has a higher probability.
The values provided in the above question are as below
Mean = = 64.3
Standard deviation = = 2.5
Step 1)
We find the probability of randomly selecting 1 woman with a height of less than 66.2 inches
---------(1)
We convert above into using following formula
----------(2)
Using equation (2) in equation (1) we get
We calculate the above probability using Standard normal table
The probability of randomly selecting 1 woman with a height of less than 66.2 inches is 0.7764
Now,
Step 2)
We find the probability of selecting a sample of 18 women with a mean height less than 66.2 inches
=
-------------(3)
We convert above into using following formula
----------------(4)
Using equation (4) in equation (3) we get
We calculate the above probability using following Excel function
=NORMSDIST(z)
Here, z = 3.224406922
=NORMSDIST(3.224406922) then press Enter we get probability as
= 0.999368831
The probability of selecting a sample of 18 women with a mean height less than 66.2 inches is 0.999368831
Or
We also calculate the above probability using Standard normal table
First we convert above into two decimal places as below
(Using Standard normal table)
The probability of selecting a sample of 18 women with a mean height less than 66.2 inches is 0.9994
Are you more likely to randomly select 1 woman with a height less than 66.2 inches or are you more likely to select a sample of 18 women with a mean height less than 66.2 inches? Choose the correct answer below.
Answer :- C. It is more likely to select a sample of 18 women with a mean height less than 66.2 inches because the sample of 18 has a higher probability.
Summary :-
Step 1)
The probability of randomly selecting 1 woman with a height of less than 66.2 inches is 0.7764
Step 2)
1) Using Excel function
The probability of selecting a sample of 18 women with a mean height less than 66.2 inches is 0.999368831
2) Using Standard normal table
The probability of selecting a sample of 18 women with a mean height less than 66.2 inches is 0.9994
Choose the correct answer below.
C. It is more likely to select a sample of 18 women with a mean height less than 66.2 inches because the sample of 18 has a higher probability.