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?
2005: \(\dfrac{23-28}3\approx-1.67\)
1965: \(\dfrac{23-18}2=2.5\)
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, \(\mu_1=28\)
Standard deviation, \(\sigma_1=3\)
Also, if x represents average turkey sold ( in pounds ),
Then x = 23
So, z-score would be,
\(z_1 =\frac{x-\mu_1}{\sigma_1}\)
\(=\frac{23-28}{3}\)
\(=-\frac{5}{3}\)
\(\approx -1.67\)
Now, mean weight in 165, \(\mu_2=18\)
\(\sigma=2\)
So, the z-score would be,
\(z_2=\frac{23-18}{2}=\frac{5}{2}=2.5\)
\(\because | -1.96 - z_1 | < |1.96 - z_2 |\)
Hence, in 1965 it will be more unusual to have a 23 pound turkey.