According to OpenSecrets.org, the net worth of U.S. senators is strongly skewed to the right. In 2010, the two measures of center for U.S. senators were $2,502,770 and $13,224,333. Which number best represents the mean net worth and which represents the median net worth of US Senators?

1. $2,502,770 is the mean and $13,224,333 is the median.
2. $2,502,770 is the median and $13,224,333 is the mean.

Question 2

Select one answer.

10 points

The Boston marathon is a very competitive race. To qualify for the Boston marathon, male runners must have completed a marathon in less than 3 hours and 5 minutes within the last year.

Other marathons, such as the Chicago marathon, have no qualifying times. Anyone is able to run this race, even without completing a different marathon earlier in the year.

Consider the groups of runners of each race: Boston marathon runners and Chicago marathon runners. Which group's finishing times for the marathon would most likely have the larger standard deviation?

1. The Chicago marathon finishing times would more likely have a higher standard deviation than the Boston marathon finishing times.
2. The Boston marathon finishing times would more likely have a higher standard deviation than the Chicago marathon finishing times.
3. They would likely have the same standard deviation because many of the same people run both races.
4. There is not enough information to predict the relative sizes of their standard deviations.

Question 3

Select one answer.

10 points

Assume that the following histograms are drawn on the same scale.

Which one of the histograms has a mean that is smaller than the median?

1. Histogram I
2. Histogram II
3. Histogram III
4. Histogram IV

Question 4

Select one answer.

10 points

Consider the data distribution given in each of the histograms. Assume that the horizontal scales are the same.

Which distribution of data has the smallest standard deviation and why?

1. Histogram I because the data values close to the mean are very small.
2. Histogram II because the distribution of data is roughly uniform.
3. Histogram III because each data distribution is symmetric with a central peak but there is not a lot of variability in heights of the bars.
4. Histogram IV because a larger proportion of the data values are clustered close to the mean.

Question 5

Select one answer.

10 points

Assume that the histograms are drawn on the same scale. Which of the histograms has the largest interquartile range (IQR)?

1. Histogram I
2. Histogram II
3. Histogram III
4. Histogram IV

Question 6

Select one answer.

10 points

The boxplots below display annual incomes (in thousands of dollars) of households in two cities.

Which city has greater variability in income?

1. Statstown
2. Medianville
3. Both cities have the same variability in income.
4. It is impossible to tell from the boxplots.

Question 7

Select one answer.

10 points

A researcher conducts an experiment to examine the effect of a new fertilizer on plant growth. She applies the fertilizer at regular intervals to 68 pepper plants. Another 59 plants receives just water.

Does the following statement provide a valid conclusion that can be drawn from the dotplots?

We cannot compare the two groups because they didn?t contain the same number of plants.

1. Valid
2. Invalid

Question 8

Select one answer.

10 points

A chemistry class has learned how to read a sensitive high-caliber balance scale (this is not a digital scale). Since most students are very good at reading the scale, the instructor decides it?s time to test their skills. The instructor asks each student to weigh the same 1.6 ounce bag of Peanut M&Ms, and then records each student?s reading of the balance scale. Which histogram shows the distribution of the students? balance-scale readings?

Which of the following statements is valid?

1. Histogram I
2. Histogram II
3. Histogram III
4. Histogram IV

Question 9

Select one answer.

10 points

Consider the data distribution given in the histogram. Which of the following tools are most appropriate to measure the center and spread for this distribution?

1. Mean and IQR
2. Median and range
3. Mean and standard deviation
4. Median and standard deviation

According to OpenSecrets.org, the net worth of U.S. senators is strongly skewed to the right. In 2010, the two measures of center for U.S. senators were $2,502,770 and $13,224,333. Which number best represents the mean net worth and which represents the median net worth of US Senators? $2,502,770 is the mean and $13,224,333 is the median. $2,502,770 is the median and $13,224,333 is the mean. Question 2 Select one answer. 10 points The Boston marathon is a very competitive race. To qualify for the Boston marathon, male runners must have completed a marathon in less than 3 hours and 5 minutes within the last year. Other marathons, such as the Chicago marathon, have no qualifying times. Anyone is able to run this race, even without completing a different marathon earlier in the year. Consider the groups of runners of each race: Boston marathon runners and Chicago marathon runners. Which group's finishing times for the marathon would most likely have the larger standard deviation? 1. The Chicago marathon finishing times would more likely have a higher standard deviation than the Boston marathon finishing times. 2. The Boston marathon finishing times would more likely have a higher standard deviation than the Chicago marathon finishing times. 3. They would likely have the same standard deviation because many of the same people run both races. 4. There is not enough information to predict the relative sizes of their standard deviations. Question 3 Select one answer. 10 points Assume that the following histograms are drawn on the same scale. Which one of the histograms has a mean that is smaller than the median? 1. Histogram I 2. Histogram II 3. Histogram III 4. Histogram IV Question 4 Select one answer. 10 points Consider the data distribution given in each of the histograms. Assume that the horizontal scales are the same. Which distribution of data has the smallest standard deviation and why? 1. Histogram I because the data values close to the mean are very small. 2. Histogram II because the distribution of data is roughly uniform. 3. Histogram III because each data distribution is symmetric with a central peak but there is not a lot of variability in heights of the bars. 4. Histogram IV because a larger proportion of the data values are clustered close to the mean. Question 5 Select one answer. 10 points Assume that the histograms are drawn on the same scale. Which of the histograms has the largest interquartile range (IQR)? 1. Histogram I 2. Histogram II 3. Histogram III 4. Histogram IV Question 6 Select one answer. 10 points The boxplots below display annual incomes (in thousands of dollars) of households in two cities. Which city has greater variability in income? 1. Statstown 2. Medianville 3. Both cities have the same variability in income. 4. It is impossible to tell from the boxplots. Question 7 Select one answer. 10 points A researcher conducts an experiment to examine the effect of a new fertilizer on plant growth. She applies the fertilizer at regular intervals to 68 pepper plants. Another 59 plants receives just water. Does the following statement provide a valid conclusion that can be drawn from the dotplots? We cannot compare the two groups because they didn't contain the same number of plants. 1. Valid 2. Invalid Question 8 Select one answer. 10 points A chemistry class has learned how to read a sensitive high-caliber balance scale (this is not a digital scale). Since most students are very good at reading the scale, the instructor decides it's time to test their skills. The instructor asks each student to weigh the same 1.6 ounce bag of Peanut M&Ms, and then records each student's reading of the balance scale. Which histogram shows the distribution of the students' balance-scale readings? Which of the following statements is valid? 1. Histogram I 2. Histogram II 3. Histogram III 4. Histogram IV Question 9 Select one answer. 10 points Consider the data distribution given in the histogram. Which of the following tools are most appropriate to measure the center and spread for this distribution? 1. Mean and IQR 2. Median and range 3. Mean and standard deviation 4. Median and standard deviation