The average turkey sold in the U.S. in 2005 weighed about 28 pounds, with a standard deviation of 3 pounds. The average in 1965 was 18 pounds, with a standard deviation of 2 pounds. At which time would it be more unusual to have a 23 pound turkey?

Respuesta :

2005: [tex]\dfrac{23-28}3\approx-1.67[/tex]

1965: [tex]\dfrac{23-18}2=2.5[/tex]

Since the 23 lb turkey is closer to the 2005 mean and further from the 1965 mean, it would be more unusual to find such a turkey in 1965. (The closer the above values (z-scores) are to zero, the more likely they are to occur.)

Answer:

In 1965

Step-by-step explanation:

If in the normal distribution, z-scores is less than -1.96 or higher than 1.96 then it is considered to be unusual.

The mean weight in 2005, [tex]\mu_1=28[/tex]

Standard deviation, [tex]\sigma_1=3[/tex]

Also, if x represents average turkey sold ( in pounds ),

Then x = 23

So, z-score would be,

[tex]z_1 =\frac{x-\mu_1}{\sigma_1}[/tex]

[tex]=\frac{23-28}{3}[/tex]

[tex]=-\frac{5}{3}[/tex]

[tex]\approx -1.67[/tex]

Now, mean weight in 165, [tex]\mu_2=18[/tex]

[tex]\sigma=2[/tex]

So, the z-score would be,

[tex]z_2=\frac{23-18}{2}=\frac{5}{2}=2.5[/tex]

[tex]\because | -1.96 - z_1 | < |1.96 - z_2 |[/tex]

Hence, in 1965 it will be more unusual to have a 23 pound turkey.