A sample of birth weights of 34 girls was taken. Below are the results (in g):
3954.1 |
3540.7 |
3594.3 |
3624.7 |
3692.8 |
3712.3 |
3390.1 |
3094 |
3606.4 |
3069 |
2737.9 |
3375.7 |
3030.9 |
3336.6 |
3910.1 |
3436.1 |
3143 |
3464.3 |
3531.6 |
3204.4 |
3301.8 |
3000.3 |
2728.3 |
3255.9 |
3421.2 |
3090.5 |
3075.5 |
3662.5 |
3869.6 |
2496.5 |
3968.5 |
3070.6 |
3237.9 |
3244.3 |
|
¯x=x¯= 3349.2 g
s=s= 354.78 g
Use a 10% significance level to test the claim that the standard deviation of birth weights of girls is less than the standard deviation of birth weights of boys, which is 480 g.
Round all answers to 3 decimal places if possible.
Procedure: Select an answer One variance χ² Hypothesis Test One proportion Z Hypothesis Test One mean Z Hypothesis Test One mean T Hypothesis Test
Step 1. Hypotheses Set-Up:
H0:H0: Select an answer σ² μ p =
Ha:Ha: Select an answer σ² p μ ? > ≠
The test is a Select an answer left-tailed two-tailed right-tailed test.
Step 2. The significance level is α=α=
Step 3. Compute the value of the test statistic: Select an answer z₀ t₀ χ₀² =
Step 4. Testing Procedure:
Provide the critical value(s) for the Rejection Region. For a one-tailed test, use DNE for the unneeded critical value.
The p-value is .
LinkOpens externally to Chi-Square Table: https://www.itl.nist.gov/div898/handbook/eda/section3/eda3674.htmOpens externally
Step 5. Decision
Is the test statistic in the rejection region? ? yes no
Is the p-value less than the significance level? ? no yes
Conclusion: Select an answer Reject the null hypothesis in favor of the alternative. Do not reject the null hypothesis in favor of the alternative.
Step 6. Interpretation:
At a 10% significance level we Select an answer do do not have sufficient evidence to reject the null hypothesis in favor of the alternative hypothesis.