Question 1

Find the standard deviation for the given data. Round your answer to one more decimal place than the original data.
22, 29, 21, 24, 27, 28, 25, 36

Accepted Answer

To find the standard deviation, first calculate the mean of the data set, then find the squared differences from the mean, average those squared differences, and finally take the square root. The calculated standard deviation is approximately 4.8.

Question 2

Six football players, all defensive linemen, decide that they will gain an average of 10 pounds over the summer. At the start of the season, only five showed up for the weigh-in. They had gained 9, 13, 11, 6, and 7 pounds. How many pounds does the last person have to gain in order that the group can attain its goal?

Accepted Answer

The answer of Six football players, all defensive linemen, decide...

Question 3

In a basketball player's first three seasons in the NBA, his field goal percentage is .340, .450, and .480. In those three seasons, the number of field goals he attempted was 80, 400, and 520 respectively. What is his career field goal percentage after three years?

Accepted Answer

The answer of In a basketball player's first three seasons...

Question 4

Which of the distributions is skewed to the right?

Accepted Answer

The answer of Which of the distributions is skewed to...

Question 5

Which one of the distributions shown below is left skewed?

Accepted Answer

The answer of Which one of the distributions shown below...

Question 6

Which one of distributions shown below has the least variation?

Accepted Answer

The answer of Which one of distributions shown below has...

Question 7

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be?

Accepted Answer

Since the students are in honors calculus, they are likely to have high and similar mathematics SAT scores, leading to a symmetric distribution with little variation.

Question 8

Alex is 80th in his class of 320 students. What is his percentile rank in class?

Accepted Answer

The answer of Alex is 80th in his class of...

Question 9

Use the range rule of thumb to approximate the standard deviation. 496, 598, 503, 528, 565, 601, 576, 543

Accepted Answer

The answer of Use the range rule of thumb to...

Question 10

The test scores of 40 students are listed below. Construct a boxplot for the data set. 
$ \begin{array}{llllllllll}25 & 35 & 43 & 44 & 47 & 48 & 54 & 55 & 56 & 57 \ 59 & 62 & 63 & 65 & 66 & 68 & 69 & 69 & 71 & 72 \ 72 & 73 & 74 & 76 & 77 & 77 & 78 & 79 & 80 & 81 \ 81 & 82 & 83 & 85 & 89 & 92 & 93 & 94 & 97 & 98\end{array} $

Accepted Answer

The answer of The test scores of 40 students are...

Question 11

The number of people waiting in the cash register lines at a local supermarket were 4, 3, 5, 4, 3, 2, 3
Find the mode(s) of these data.

Accepted Answer

The answer of The number of people waiting in the...

Question 12

Which of the distributions is multimodal?

Accepted Answer

The answer of Which of the distributions is multimodal?

...

Question 13

In testing a new light bulb design, 6 bulbs were left on until they burned out or 2000 hours whichever came first. One bulb had not burned out by the end of the test, so 2000 hours was Recorded for that bulb. If the testers had waited for that bulb to burn out, what would have Happened to the mean and median lives of the bulbs?

Accepted Answer

The mean would increase because the actual burnout time would be greater than 2000 hours, increasing the total sum of hours. The median would not change because it is the middle value, and the order of the other values remains the same.

Question 14

Amtrak trains from Chicago to Portland arrived at Havre, MT, where they make a crew change, the following numbers of minutes late.
26, 17, 245, 19, 38, 42, 11, 0, 14, 44
Find the mean number of minutes late at Havre (to one decimal place).

Accepted Answer

The answer of Amtrak trains from Chicago to Portland arrived...

Question 15

Randomly selected voters leaving the polls identified themselves as Republican (R), Democrat (D), or Independent (I). The data were 
R R I D D D I R D D I R R D D
D D I I R I R I D D R I R D I 
What is the mode of these data?

Accepted Answer

The answer of Randomly selected voters leaving the polls identified...

Question 16

Al and Joe are two county sheriff's deputies assigned to watch for traffic violations. Their arrest and conviction records for May and June are shown below.

$$\begin{array} {c}
  \quad \quad \quad { \text { May } }    \quad \quad\quad \quad \quad{ \text { June } } \
\begin{array} { | l | l | l | l | l | }

\hline & \text { Arrests } & \text { Convictions } & \text { Arrests } & \text { Convictions } \
\hline\text { Al } & 10 & 1 & 80 & 41 \
\hline \text { Joe } & 90 & 30 & 20 & 12 \
\hline
\end{array}\end{array}$$ Who had the best conviction percentage in May?
Who had the best conviction percentage in June?
Who had the best conviction percentage overall?

Accepted Answer

The answer of Al and Joe are two county sheriff's...

Question 17

The salaries of randomly selected bank employees were
 $$\begin{array} { l l l l l } 
\$ 23,540 & \$ 82,500 & \$ 37,360 & \$ 24,670 & \$ 19,810 \
\$ 33,140 & \$ 22,940 & \$ 27,420 & \$ 47,130 & \$ 29,290
\end{array}$$ 
Find the median salary of these employees.

Accepted Answer

The answer of The salaries of randomly selected bank employees...

Question 18

Randomly selected high school seniors had the following numbers of one-dollar bills in their wallets.
2, 4, 3, 7, 5, 4, 5, 2, 9, 17, 0, 4, 7, 6, 8
Find the median number of one-dollar bills.

Accepted Answer

The answer of Randomly selected high school seniors had the...

Question 19

A trout hatchery had more 4 year-old fish than they could use one year, so they held about 1000 of them over until the next year. The hatchery routinely moved fish from one pond to the next each year and 10,000 three-year old fish were placed in the pond with the leftover four-year old fish. When the fish were finally taken out of the pond for releasing into streams, what would the distribution of the weights of the released fish look like? Describe the
distribution as well as you can and draw a picture.

Accepted Answer

The answer of A trout hatchery had more 4 year-old...

Question 20

Suppose that your income is at the 81st percentile of wage earners in the United States. What percent of wage earners make more than you do?

Accepted Answer

If your income is at the 81st percentile, it means you earn more than 81% of wage earners, so 19% earn more than you.

Quiz 4: Describing Data

Find the standard deviation for the given data. Round your answer to one more decimal place than the original data. 22, 29, 21, 24, 27, 28, 25, 36

In a basketball player's first three seasons in the NBA, his field goal percentage is .340, .450, and .480. In those three seasons, the number of field goals he attempted was 80, 400, and 520 respectively. What is his career field goal percentage after three years?

Which of the distributions is skewed to the right?

Which one of the distributions shown below is left skewed?

Which one of distributions shown below has the least variation?

Consider the distribution of mathematics SAT scores of students in honors calculus at a liberal arts college. What would you expect the shape and variation of the distribution to be?

Alex is 80th in his class of 320 students. What is his percentile rank in class?

Use the range rule of thumb to approximate the standard deviation. 496, 598, 503, 528, 565, 601, 576, 543

The number of people waiting in the cash register lines at a local supermarket were 4, 3, 5, 4, 3, 2, 3 Find the mode(s) of these data.

Which of the distributions is multimodal?

Amtrak trains from Chicago to Portland arrived at Havre, MT, where they make a crew change, the following numbers of minutes late. 26, 17, 245, 19, 38, 42, 11, 0, 14, 44 Find the mean number of minutes late at Havre (to one decimal place).

Randomly selected voters leaving the polls identified themselves as Republican (R), Democrat (D), or Independent (I). The data were R R I D D D I R D D I R R D D D D I I R I R I D D R I R D I What is the mode of these data?

The salaries of randomly selected bank employees were $\begin{array} { l l l l l } \$ 23,540 & \$ 82,500 & \$ 37,360 & \$ 24,670 & \$ 19,810 \\\$ 33,140 & \$ 22,940 & \$ 27,420 & \$ 47,130 & \$ 29,290\end{array}$ Find the median salary of these employees.

Randomly selected high school seniors had the following numbers of one-dollar bills in their wallets. 2, 4, 3, 7, 5, 4, 5, 2, 9, 17, 0, 4, 7, 6, 8 Find the median number of one-dollar bills.

Suppose that your income is at the 81st percentile of wage earners in the United States. What percent of wage earners make more than you do?