Can anyone help me with a business statistics question?

I can't understand my professor, and he's a bad teacher at that





question is





Does cocaine use by prgnant women cause their babies to have low birth weight? To study this question, birth weights of babies of women who tested positive for cocaine during a drug screening test were compared with the birth weights for women who either tested negative or were not tested, a group we cal 'other'. Here are the summary statistics. The birth weights are measured in grams





Positive test group, n=134, x bar = 2733, s=599


Other n=5974, x bar=3118, s =672





I doubt anyone will answer this, but if anyone does i appreciate it, i just don't get any of it.

Can anyone help me with a business statistics question?
i lost u at the question is...


plz rate as bestest ever cuz it issss!!!
Reply:OK. one step at a time


1) breathe


2) understand the question: does cocaine use cause low birth weight


3) what is normal birth weight? other's x bar (mean) is 3118


4) what to compare to? in the other group, going out 1 standard deviation in either direction (s) gives you a range of 68% of the population. which means that 68% of other birth rates are between 2446 and 3790 (x bar +/- s)


5) understand the results: the sample population mean (2733)is well within range of the population mean (3118)


6) translation to answer question: cocaine does NOT cause low birth weight


7) reasoning and explanation: at first glance, it seems like the answer should be less. however, the size of the sample compared to the population sample means that there will be a wider range of birth weights to make the shape of a bell curve. Where the sample means falls along the curve is just to the left of the middle making it reasonable to conclude that the weights are within the normal range.


8) breathe again, cuz now it's done.





I hope this helps!
Reply:Sorry cant answer that cause my mommy wint let me....
Reply:where x bar is the birth weight and s is the standard deviation? n is sample size?





Looks like you have a higher s in the other group and a lower birth weight. so I'd say the answer is yes
Reply:This is a large sample test for the difference in means.





the null hypothesis is H0: μ1 - μ2 ≥ 0


the alternate hypothesis is H1: μ1 - μ2 %26lt; 0





the test statistic is:





z = (xbar1 - xbar2) / (√( s1² / n1 + s2² / n2 ))


z = (2733 - 5974) / √( 599² / 134 + 672² / 5974 )


z = -3241 / 52.47105


z = -61.76739





the p-value for the test is:





p-value = P(Z %26lt; -61.76739) ≈ 0. in fact this probability is so low you could say it equals 0.





with such a small p-value we reject H0 and conclude H1 is true and that the positive test group has a smaller mean than the other test group.
Reply:NEVER DO DRUGS!

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