Ascientist is studying the effects of cell phone use on headache rate. she identifies 30 people who use cell phones and 30 who do not. each of the 60 people is given a questionnaire designed to determine headache frequency. none of the 60 people who participated in the study knew they were part of a study. which statement is true? (5 points) question 5 options: 1) this is a randomized comparative experiment. 2) this is an observational study. 3) this is a double-blind study. 4) this is a matched-pairs design.

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.

Arecent study focused on the number of times men and women who live alone buy take-out dinner in a month. assume that the distributions follow the normal probability distribution and the population standard deviations are equal. the information is summarized below. statistic men women sample mean 24.85 21.33 sample standard deviation 5.54 4.93 sample size 34 36 at the 0.01 significance level, is there a difference in the mean number of times men and women order take-out dinners in a month? state the decision rule for 0.01 significance level: h0: μmen= μwomen h1: μmen ≠ μwomen. (negative amounts should be indicated by a minus sign. round your answers to 3 decimal places.) compute the value of the test statistic. (round your answer to 3 decimal places.) what is your decision regarding the null hypothesis? what is the p-value? (round your answer to 3 decimal places.)

Right ∆abc has coordinates a(-7, 3), b( -7, 10), and c(-1, 3). the triangle is reflected over the x - axis and then reflected again over the y - axis to create ∆a'b'c'. which are the coordinates of vertex a'?