Have American males (AMs) gotten heavier over the last 20 years? A random sample 77 AMs in 2019 had a mean weight of x = 189.030 pounds. A random sample 93 AMs in 1999 had a mean weight of y = 184.795 pounds. It is recognized that the true standard deviation of 2019 AMs weights is σx = 14.04 pounds while it is recognized that the true standard deviation of 1999 AMs weights is σy = 10.03 pounds. The true (unknown) mean of 2019 AMs weights is μx pounds, while the true (unknown) mean of 1999 AMs weights is μy pounds. Weights are known to be a normally distributed. In summary: Type Sample Size Sample Mean Standard Deviation 2019 Data (X) 77 189.030 14.04 1999 Data (Y) 93 184.795 10.03 d) Calculate the standard deviation of X - Y? . e) If we wish to create an 98% confidence interval for μx-μy then what is the z critical value used? f)Create an 98% confidence interval for μx-μy .
Have American males (AMs) gotten heavier over the last 20 years? A random sample 77 AMs in 2019 had a mean weight of x = 189.030 pounds. A random sample 93 AMs in 1999 had a mean weight of y = 184.795 pounds. It is recognized that the true standard deviation of 2019 AMs weights is
= 14.04 pounds while it is recognized that the true standard deviation of 1999 AMs weights is
= 10.03 pounds. The true (unknown) mean of 2019 AMs weights is
pounds, while the true (unknown) mean of 1999 AMs weights is
pounds. Weights are known to be a
| Type | Sample Mean | Standard Deviation | |
|---|---|---|---|
| 2019 Data (X) | 77 | 189.030 | 14.04 |
| 1999 Data (Y) | 93 | 184.795 | 10.03 |
d) Calculate the standard deviation of X - Y?
.
e) If we wish to create an 98% confidence interval for
then what is the z critical value used?
f)Create an 98% confidence interval for
.
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