Question

The age of patients is normally distributed with a mean of 44.9 and standard deviation of 12.6. Researchers would like to compare the results of this study to a previous study. In the previous study the mean age of patients was 67.2 years. The hypothesis is if there evidence that the participants in this study are of significantly different age. n=25

What are the value for t and p-value?

Answer 1

Sample size = n = 25

Sample mean = = 44.9

Standard deviation = s = 12.6

Claim: The participants in this study are of significantly different age.

The null and alternative hypothesis is

Level of significance = 0.05

Here population standard deviation is unknown so we have to use t-test statistic.
Test statistic is

Degrees of freedom = n - 1 = 25 - 1 = 24

P-value = 2*P(T < - 8.85) = 0.0000

P-value < 0.05 we reject null hypothesis.

Conclusion:

The participants in this study are of significantly different age.