52 902
Assignments Done
97,8%
Successfully Done
In October 2017
Your physics homework can be a real challenge, and the due date can be really close — feel free to use our assistance and get the desired result.
Be sure that math assignments completed by our experts will be error-free and done according to your instructions specified in the submitted order form.

# Answer on Statistics and Probability Question for tami

Question #3727
Do a two sample t test. Assume that this is a two sided test with alpha 5%. &lt;br&gt;Find the test stat, p-value and make a decision about the null.
Null hypothesis is that the difference between the two groups is 0.
Alternative hypothesis - the difference between two means is not zero.

Test statistics can be found by the formula

$\frac{\bar{x_1} - \bar{x_2}}{\sqrt{\frac{SD_1^2}{n_1}+ \frac{SD_2^2}{n_2}}}$
where x1, x2 - are the means of two samples, SD1,2 - standard deviations , n1,2 - the number of observations of two samples respectively.
Then you have to calculate the number of degrees of freedom:

$d.f. = \frac{(SD_1^2/n_1 + SD^2_2 /n_2)^2}{(SD^2_1/n_1)^2/(n_1 -1) + (SD^2_2/n_2)^2/(n_2 -1)}$
and find p-value from the tables (or using t to p value calculator).
If p-value is more than 0.1 (performing two-sided test you must use doubled alpha), we do not reject the null hypothesis; otherwise - we reject it.

Need a fast expert's response?

Submit order

and get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!