Question

A clinical trial tests a method designed to increase the probability of conceiving a girl. In the study 520 babies were born, and 286 of them were girls. Use the sample data to construct a 99% confidence interval estimate of the percentage of girls born. Based on the result, does the method appear to be effective?
__< P < __

Answer 1

what do you believe our hypothesis should be?

Answer 2

By finding the standard deviation and the mean I know for sure

Answer 3

those are already presented to yo in the problem, the first step is determining what our hypothesises should be so we know what we are testing for

Answer 4

i may be confusing this with a hypothesis test ... its simple to misread it :)

what is out mean?

Answer 5

and in this case its called a proportion, the trials produced a proportion of girls born.

Answer 6

Oh ok

Answer 7

How can I find that on the TI83?

Answer 8

theres a 1 sample proportion test

id have to find it again, its either a stat test under th elist menu or a side menu under 2nd vars

Answer 9

Ok thank you

Answer 10

hit the stat button

Answer 11

arrow over to "tests"

arrow down to the 1 propZtest

Answer 12

its asks for n, p, and confidence level

Answer 13

hmm, thats still a hypothesis test tho

Answer 14

our interval itself is:
\[\frac xn \pm z\sqrt{\frac{x(n-x)}{n^3}}\]
assuming of course we use the trial data

Answer 15

your: __ < P < ___ is a little odd to me.

it looks like its asking for a confidence interval