Question 1

Find the sample standard deviation s for the following sample data. Round your answer to the nearest hundredth. $\begin{array}{llllll}
x: & 24 & 17 & 15 & 33 & 25
\end{array}$

Accepted Answer

A) 7.16 
B) 8.57 
C) 9.58 
D) 6.40 
E) 9.60 
A) 7.16 
B) 8.57 
C) 9.58 
D) 6.40 
E) 9.60

Question 2

Compute the population standard deviation $\sigma$ for the following sample data, assuming the sample comprises the entire population. Round your answer to the nearest hundredth. x:
21
17
15
35
27

Accepted Answer

A) 8.12 
B) 10.36 
C) 2.30 
D) 9.27 
E) 9.22 
A) 8.12 
B) 10.36 
C) 2.30 
D) 9.27 
E) 9.22

Question 3

Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute the sample mean for x and for y. Round your answer to the nearest tenth. $$\begin{array} { l l l l l l l l l l l } 
x : & 13 & 0 & 37 & 25 & 32 & 27 & 28 & - 13 & - 13 & - 25 \
y & 8 & - 2 & 26 & 16 & 26 & 18 & 16 & - 2 & - 3 & - 8
\end{array}$$

Accepted Answer

A) and $\bar { x } = 68.5$ $\bar { y } = 9.9$ 
B) and $\bar { x } = 11.1$ $\bar { y } = 9.5$ 
C) and $\bar { x } = 161.0$ $\bar { y } = 10.6$ 
D) and $\bar { x } = 39.5$ $\bar { y } = 13.0$ 
E) and $\bar { x } = 9.5$ $\bar { y } = 11.1$ 
A) and $\bar { x } = 68.5$ $\bar { y } = 9.9$ 
B) and $\bar { x } = 11.1$ $\bar { y } = 9.5$ 
C) and $\bar { x } = 161.0$ $\bar { y } = 10.6$ 
D) and $\bar { x } = 39.5$ $\bar { y } = 13.0$ 
E) and $\bar { x } = 9.5$ $\bar { y } = 11.1$

Question 4

Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for the Vanguard Total Stock Index (all Stocks). Let y be a random variable representing annual return for the Vanguard Balanced Index (60% stock and 40% bond). For the past several years, assume the following data. Compute. $$\sum y$$ $$\begin{array} { l l c l l l l l l l l } 
x : & 12 & 0 & 39 & 25 & 33 & 27 & 28 & - 12 & - 12 & - 25 \
y : & 7 & - 1 & 29 & 15 & 26 & 18 & 15 & - 1 & - 2 & - 7
\end{array}$$

Accepted Answer

A) 106 
B) 100 
C) 99 
D) 101 
E) 107 
A) 106 
B) 100 
C) 99 
D) 101 
E) 107

Question 5

At Center Hospital there is some concern about the high turnover of nurses. A survey was done to determine how long (in months) nurses had been in their current positions. The responses (in months) of 20 nurses were Find the interquartile range.
$$\begin{array} { l l l l l l l l l l } 
27 & 3 & 7 & 20 & 28 & 38 & 31 & 45 & 19 & 11 \
9 & 19 & 35 & 30 & 33 & 16 & 25 & 37 & 13 & 38
\end{array}$$

Accepted Answer

A) 46.5 
B) 19.5 
C) 22.5 
D) 48.5 
E) 21.5 
A) 46.5 
B) 19.5 
C) 22.5 
D) 48.5 
E) 21.5

Question 6

Suppose automobile insurance companies gave annual premiums for top-rated companies in several states. The figure below shows box plots for the annual premium for urban customers in three states.   Which state has the smallest range of premiums?

Accepted Answer

A) Texas has the smallest range of premiums. 
B) California has the smallest range of premiums. 
C) Texas as well as Pennsylvania have the smallest range. 
D) Pennsylvania has the smallest range of premiums. 
E) none of these choices 
A) Texas has the smallest range of premiums. 
B) California has the smallest range of premiums. 
C) Texas as well as Pennsylvania have the smallest range. 
D) Pennsylvania has the smallest range of premiums. 
E) none of these choices

Find the sample standard deviation s for the following sample data. Round your answer to the nearest hundredth. x: 24 17 15 33 25

Compute the population standard deviation $\sigma$ for the following sample data, assuming the sample comprises the entire population. Round your answer to the nearest hundredth. x: 21 17 15 35 27

Suppose automobile insurance companies gave annual premiums for top-rated companies in several states. The figure below shows box plots for the annual premium for urban customers in three states. Which state has the smallest range of premiums?

Getting Started

Organizing Data

Correlation and Regression

Elementary Probability Theory

The Binomial Probability Distribution and Related Topics

Normal Curves and Sampling Distributions

Estimation

Hypothesis Testing

Inferences About Differences

Additional Topics Using Inference

Filters

Exam 3: Averages and Variation