Question 190466: A study of iron deficiency among infants compared samples of infants following different
feeding regimens. One group contained breast-fed infants, while the children in other group
were fed a standard baby formula without any iron supplements. Here are summary results
on blood hemoglobin levels at 12 months of age.
Group n Mean s
Breast-fed 23 13.3 1.7
Formula 19 12.4 1.8
a. Is there significant evidence that the mean hemoglobin level is higher among breastfed
babies? State null hypothesis and alternate hypothesis and conduct a t-test.
b. Give a 95% confidence interval for the mean difference in hemoglobin level between
the two populations of infants.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A study of iron deficiency among infants compared samples of infants following different
feeding regimens. One group contained breast-fed infants, while the children in other group
were fed a standard baby formula without any iron supplements. Here are summary results
on blood hemoglobin levels at 12 months of age.
Group...... n Mean s
Breast-fed 23 13.3 1.7
Formula... 19 12.4 1.8
a. Is there significant evidence that the mean hemoglobin level is higher among breastfed babies? State null hypothesis and alternate hypothesis and conduct a t-test.
Ho: u(breastfed)-u(formula) = 0
Ha: u(breastfed)-u(formula > 0
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I ran a 2-sample T-test on a TI caluclator and got the following:
test statistic: t= 1.6537
p-value.......: P(t.1.6537 with df=37.6) = 0.05325
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Conclusion: Since the p-value is greater than 5%, fail to reject Ho.
Note: The p-value is so close to 5% more testing should be done.
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b. Give a 95% confidence interval for the mean difference in hemoglobin level between the two populations of infants.
I ran a 2-Sample T-interval on a TI caluculator and got the folowing
95% C.I.:::: ( -0.2021 , 2.0021)
Conclusion: Since zero is in the 95% C.I., fail to reject Ho.
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Cheers,
Stan H.
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