Which one of the following variables is not categorical?
Which of the following would be most likely to produce selection bias in a survey?
What is one of the distinctions between a population parameter and a sample statistic?
If a statistically significant difference in blood pressure, change at the end of a year for the two activities was found, then?
The two treatments in this study were?
Scenario: A randomized experiment was done by randomly assigning each participant either to walk for half an hour three times a week or to sit quietly reading a book for half an hour three times a week. At the end of a year, the change in Participants blood pressure over the year was measured, and the change was compared for the two groups.?
Which of the following is a confounding variable in this study?
Scenario: A study was done to compare the lung capacity of coal miners to the lung capacity of farm workers. The researcher studied 200 workers of each type. Other factors that might affect lung capacity are smoking habits and exercise habits. The smoking habits of the two worker types are similar, but the coal miners generally exercise less than the farm workers do?
A polling agency conducted a survey of 100 doctors on the question �Are you willing to treat women patients with the recently approved pill RU-486�. The conservative margin of error associated with the 95% confidence interval for the percent who say yes is?
Which one of these statistics is unaffected by outliers?
A list of 5 pulse rates is: 70, 64, 80, 74, 92. What is the median for this list?
Which of the following would indicate that a dataset is not bell-shaped?
A scatter plot of number of teachers and number of people with college degrees for cities in California reveals a positive association. The most likely explanation for this positive Association is?
The value of a correlation is reported by a researcher to be r = -0.5. Which of the following statements is correct?
What is the effect of an outlier on the value of a correlation coefficient?
One use of a regression line is?
Past data has shown that the regression line relating the final exam score and the midterm exam score for students who take statistics from a certain professor is: Final exam = 50 + 0.5 � midterm. One interpretation of the slope is?
Scenario: A survey asked people how often they exceed speed limits. The data are then categorized into the following contingency table of counts showing the relationship between age group and response.
Exceed Limit if Possible Age Always Not Always Total
Under 30 100 100 200
Over 30 40 160 200
Total 140 260 400
Among people with age over 30, what is the risk of always exceeding the speed limit?
Among people with age under 30 what are the odds that they always exceed the speed limit?
Scenario: A newspaper article reported, Children who routinely compete in vigorous after-school sports on smoggy days are three times more likely to get asthma than their non-athletic peers. (Sacramento Bee, Feb 1, 2002, p. A1) Of the following, which is the most important additional information that would be useful before making a decision about participation in school sports?
The newspaper also reported, The number of children in the study who contracted asthma was relatively small Answer - 265 of 3,535. From this information and the information given in the original quote, which of the following could not be computed?
Scenario: The following histogram shows the distribution of the difference between the actual and �ideal� weights for 119 female students. Notice that percent is given on the vertical axis. Ideal weights are responses to the question �What is your ideal weight�. The difference = actual -ideal.
What is the approximate shape of the distribution?
The median of the distribution is approximately?
Most of the women in this sample felt that their actual weight was?
A chi-square test of the relationship between personal perception of emotional health and marital status led to rejection of the null hypothesis, indicating that there is a relationship between these two variables. One conclusion that can be drawn is?
A chi-square test involves a set of counts called �expected counts.� What are the expected counts?
Pick the choice that best completes the following sentence. If a relationship between two variables is called statistically significant, it means the investigators think the variables are?
Simpsons Paradox occurs when?