Question 1115361: State the null and alternative null hypothesis:
Does cocaine use by pregnant women cause their babies to have lower birth weight? To study this question, birth weights of babies of women who tested positive for cocaine/crack during a drug screening test were compared with the birth weights for women who either tested negative or were not tested, a group we call “other.” Here are the summary statistics. The birth weights are measured in grams. Data are from a study conducted at the Medical University of South Carolina in 1989. Do not pool.
Positive test - n=134, mean = 2733, std. dev = 599
Other - n=5974, mean = 3118, std. dev= 672
I got:
H₀: μpositive-μother=0 for null and
H₀: μpositive-μother<0 for alternative
I just need to know if this is correct or not and why I would equate the hypothesis to 0
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! State the null and alternative null hypothesis:
Does cocaine use by pregnant women cause their babies to have lower birth weight? To study this question, birth weights of babies of women who tested positive for cocaine/crack during a drug screening test were compared with the birth weights for women who either tested negative or were not tested, a group we call “other.” Here are the summary statistics. The birth weights are measured in grams. Data are from a study conducted at the Medical University of South Carolina in 1989. Do not pool.
Positive test - n=134, mean = 2733, std. dev = 599
Other - n=5974, mean = 3118, std. dev= 672
I got:
H₀: μpositive-μother=0 for null and
Ha: μpositive-μother<0 for alternative
I just need to know if this is correct or not and why I would equate the hypothesis to 0
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You are correct.
Your Ho says the crack made no difference in the wt. of the baby.
Your Ha says the babies of the crack users is less than that of the none users.
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Cheers,
Stan H.
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