Question 1
A survey asked people "On what percent of days do you get more than 30 minutes of vigorous exercise?" Using their responses we want to estimate the difference in exercise frequency between men and women. We should use a
◦ 1-sample t-interval
◦ matched pairs t-interval
◦ 2-sample t-interval
◦ 1-proportion z-interval
◦ 2-proportion z-interval
Question 2
Two agronomists analyzed the same data, testing the same null hypothesis about the proportion of tomato plants suffering from blight. One rejected the hypothesis but the other did not. Assuming neither made a mistake in calculations, which of these possible explanations could account for this apparent discrepancy?
I. One agronomist wrote a one-tailed alternative hypothesis, but the other used 2 tails.
II. They wrote identical hypotheses, but the one who rejected the null used a higher α-level.
III. They wrote identical hypotheses, but the one who rejected the null used a lower α-level.
◦ I only
◦ I or III
◦ III only
◦ II only
◦ I or II
Pressure-flow hypothesis for phloem transport
The nitrogen cycle. Numbers represent fluxes as 1012 g N per year (data from Schlesinger 1991, after
Design Data for Various Packings
How to find the quartiles and percentiles for a data set
The wobble hypothesis
E chart for testing distant vision