Question

ch 23* in an experiment to learn if substance m can help restore memory, the brains of 20 rats were treated to damage their memories. the rats were trained to run a maze. after a day, 10 rats were given m, and seven of them succeeded in the maze; only two of the 10 control rats were successful. the z test for this scenario
may be inaccurate because some counts of successes and failures are too small.
may be inaccurate because the populations are too small.
is reasonably accurate because the conditions for inference are met.
question 15
1 pts
ch 23 in a pooled sample proportion, two samples are combined to estimate this single p instead of estimating p1 and p2 separately.
true
false
question 16
1 pts
ch 23 a candidate for one of ohios two u.s. senate seats wishes to compare her support among registered voters in the northern half of the state with her support among registered voters in the southern half of the state. a random sample of 2000 registered

Explanation:

For Question 15, in a pooled - sample proportion, when we assume \(p_1 = p_2=p\) (the null hypothesis in a two - proportion \(z\) - test), we combine the two samples to estimate the common proportion \(p\) instead of estimating \(p_1\) and \(p_2\) separately. The formula for the pooled proportion \(\hat{p}=\frac{x_1 + x_2}{n_1 + n_2}\), where \(x_1\) and \(x_2\) are the number of successes in the two samples and \(n_1\) and \(n_2\) are the sample sizes.

Answer:

Question 15: True