Question

question 14 1 pts ch 17 in formulating hypotheses for a statistical test of significance, the null hypothesis, ho, is often a statement of
o effect\ or
o difference.\ the probability of observing the data you actually obtained. a statement that the data are all 0. a statement of \difference\. question 15 1 pts ch 17* researchers investigated the effectiveness of oral zinc, as compared to a placebo, in reducing the duration of the common cold when taken within 24 hours of the onset of symptoms. the researchers found those taking oral zinc had a statistically significantly shorter duration than those taking the placebo. this means that the value of the test statistic, which is the mean reduction in duration of the cold, is large. true

Explanation:

1. For Question 14: The null hypothesis ($H_0$) in a statistical - test of significance is typically a statement of "no effect" or "no difference". It represents the status - quo or default position. The other options are incorrect as the probability of observing the data is related to the p - value, not the null hypothesis, and the null hypothesis is not about all data being 0 or a statement of difference.
2. For Question 15: In a statistical test, if the result is statistically significant, it means that the test statistic is large enough to reject the null hypothesis. Here, the fact that those taking oral zinc had a statistically significantly shorter duration than those taking the placebo implies that the value of the test statistic (the mean reduction in duration of the cold) is large.

Answer:

Question 14: A. a statement of "no effect" or "no difference."
Question 15: True