nicollehall
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- Joined
- Jan 6, 2011
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I have been in this statistics course for four weeks, and i am beginning to sink. Please help!!!
A researcher wants to prove that average age when women first marry has increased from 1960 to 1990. Let = average age of first marriage for women in 1990 and = average age of first marriage for women in 1960. A random sample of 10 women married in 1990 showed an average age at marriage of 24.95 years, with a sample standard deviation of 2 years. A random sample of 20 women married in 1960 showed an average age at marriage of 23.1 years, with a sample standard deviation of 1.5 years. Assume that age of first marriage for women is normally distributed, but do not assume the population variances are equal. Use the conservative “by hand” estimate for the degrees of freedom.
1. What are the appropriate null and alternative hypotheses?
2. What is the value of the test statistic?
3. What is the p-value?
4. For a significance level of alpha = 0.05, are the results statistically significant?
5. Report your conclusion.
Choose one answer.
a. The average age of first marriage for women in 1990 is greater than the average age in 1960.
b. The results are not statistically significant: there is not enough evidence to conclude that the average age in 1990 is greater than the average age in 1960.
c. The average age of marriage is at least 23 years old for both 1960 and 1990.
d. None of the above.
I am so stuck, I have failed at comprehending the mathmatical language and feel like I have hit a brick wall. Please Please Help!!!!
A researcher wants to prove that average age when women first marry has increased from 1960 to 1990. Let = average age of first marriage for women in 1990 and = average age of first marriage for women in 1960. A random sample of 10 women married in 1990 showed an average age at marriage of 24.95 years, with a sample standard deviation of 2 years. A random sample of 20 women married in 1960 showed an average age at marriage of 23.1 years, with a sample standard deviation of 1.5 years. Assume that age of first marriage for women is normally distributed, but do not assume the population variances are equal. Use the conservative “by hand” estimate for the degrees of freedom.
1. What are the appropriate null and alternative hypotheses?
2. What is the value of the test statistic?
3. What is the p-value?
4. For a significance level of alpha = 0.05, are the results statistically significant?
5. Report your conclusion.
Choose one answer.
a. The average age of first marriage for women in 1990 is greater than the average age in 1960.
b. The results are not statistically significant: there is not enough evidence to conclude that the average age in 1990 is greater than the average age in 1960.
c. The average age of marriage is at least 23 years old for both 1960 and 1990.
d. None of the above.
I am so stuck, I have failed at comprehending the mathmatical language and feel like I have hit a brick wall. Please Please Help!!!!
