Question 1

Use a table of areas to find the specified area under the standard normal curve.
-The area that lies between -0.73 and 2.27

Accepted Answer

A) 0.4884 
B) 0.7557 
C) 1.54 
D) 0.2211 
A) 0.4884 
B) 0.7557 
C) 1.54 
D) 0.2211

Question 2

Find the indicated probability or percentage for the normally distributed variable.
-The variable $X$ is normally distributed.The mean is $\mu = 22.0$ and the standard deviation is $\sigma = 2.4$. Find $P ( 19.7 < X < 25.3 )$.

Accepted Answer

A) $0.7477$ 
B)  $1.0847$ 
C)  $0.4107$ 
D)  $0.3370$ 
A) $0.7477$ 
B)  $1.0847$ 
C)  $0.4107$ 
D)  $0.3370$

Question 3

Provide an appropriate response. Assume that the variable under consideration has a density curve.
-The area under the density curve that lies to the right of 12 is 0.405. What percentage of all possible observations of the variable are at most 12?

Accepted Answer

A) 65.5% 
B) 59.5% 
C) 40.5% 
D) 34.5% 
A) 65.5% 
B) 59.5% 
C) 40.5% 
D) 34.5%

Question 4

Suppose that you know the area under the standard normal curve to the right of -2. How could you use this to find the area under the standard normal curve to the left of 2? Explain your reasoning.

Accepted Answer

By symmetry, the area under th

Question 5

Use a table of areas to obtain the shaded area under the standard normal curve.
-

Accepted Answer

A) $0.8790$ 
B)  $0.1210$ 
C)  $0.7580$ 
D)  $0.2420$ 
A) $0.8790$ 
B)  $0.1210$ 
C)  $0.7580$ 
D)  $0.2420$

Question 6

Fill in the blanks by standardizing the normally distributed variable.
-The amount of time that customers wait in line during peak hours at one bank is normally distributed with a mean of 15 minutes and a standard deviation of 2 minutes. The percentage of
Time that the waiting time is less than 11 minutes is equal to the area under the standard normal
Curve that lies to the ___ of ___.

Accepted Answer

A) right, 0.6 
B) right, -2 
C) left, -2 
D) left, 2 
A) right, 0.6 
B) right, -2 
C) left, -2 
D) left, 2

Question 7

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to identify outliers, if any. Explain your reasoning.

Accepted Answer

The point (100, 1.5)appears to

Question 8

Use the empirical rule to solve the problem.
-The amount of Jen's monthly phone bill is normally distributed with a mean of $78 and a standard deviation of $8. Fill in the blanks.
68.26% of her phone bills are between $___ and $___.

Accepted Answer

A) 70, 86 
B) 62, 78 
C) 78, 86 
D) 62, 94 
A) 70, 86 
B) 62, 78 
C) 78, 86 
D) 62, 94

Question 9

A normal probability plot is given below for the weekly incomes (in dollars)of a sample of engineers in one town. Use the plot to assess the normality of the incomes of engineers in this town. Explain your reasoning.

Accepted Answer

Since the normal probability p

Question 10

For a variable with a density curve, what is the relationship between the percentage of all possible observations of the variable that lie within any specified range and the corresponding area under its density curve?

Accepted Answer

They are equal (at l

Question 11

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution.
-Two percent of hair dryers produced at a certain plant are defective. Estimate the probability that of 10,000 randomly selected hair dryers, the number of defectives is between 195 and 210 inclusive.

Accepted Answer

A) 0.4251 
B) 0.4034 
C) 0.4017 
D) 0.3989 
A) 0.4251 
B) 0.4034 
C) 0.4017 
D) 0.3989

Question 12

Use a table of areas to find the specified area under the standard normal curve.
-The area that lies either to the left of 1.56 or to the right 2.30

Accepted Answer

A) 0.0701 
B) 0.9299 
C) 0.9513 
D) 0.0487 
A) 0.0701 
B) 0.9299 
C) 0.9513 
D) 0.0487

Question 13

A variable is normally distributed. 42% of the possible observations of the variable lie between 20 and 28. What information does this give you about the graph of the normal curve for this variable?

Accepted Answer

The area under the n

Question 14

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution.
-A product is manufactured in batches of 120 and the overall rate of defects is 5%. Estimate the probability that a randomly selected batch contains more than 6 defects.

Accepted Answer

A) 0.4168 
B) 0.4641 
C) 0.5871 
D) 0.0832 
A) 0.4168 
B) 0.4641 
C) 0.5871 
D) 0.0832

Question 15

Construct a normal probability plot of the given data.
-The prices per gallon (in dollars)of regular unleaded gasoline at twelve service stations are given below.  
$\begin{array}{llll} 1.79 & 2.09 & 1.89 & 1.99 \ 1.75 & 1.81 & 1.93 & 2.19 \ 2.01 & 2.15 & 1.95 & 1.85 \end{array}$

Accepted Answer

The answer of Construct a normal probability plot of the...

Question 16

Solve the problem.
-Data were reported for household size (number of people in household)in a small community. The size distribution is given in the table. Obtain a relative-frequency histogram for these data and Determine whether the household sizes are approximately normally distributed. $\begin{array}{c|c}
\text { Size } & \text { Frequency } \
\text { (\# of people) } & \
\hline \text { 1-under 2 } & 2 \
\text { 2-under 3 } & 11 \
\text { 3-under 4 } & 35 \
\text { 4-under 5 } & 41 \
\text { 5-under 6 } & 7 \
\text { 6-under 7 } & 3
\end{array}$

Accepted Answer

A) No. The distribution is uniform. 
B) Yes. The distribution is bell-shaped. 
C) No. The distribution is left-skewed. 
D) No. The distribution is right-skewed. 
A) No. The distribution is uniform. 
B) Yes. The distribution is bell-shaped. 
C) No. The distribution is left-skewed. 
D) No. The distribution is right-skewed.

Question 17

Construct a normal probability plot of the given data.
-The systolic blood pressure (in mmHg)is given below for a sample of 12 men aged between 60 and 65.  
$\begin{array}{llll} 127 & 135 & 118 & 164 \ 143 & 130 & 125 & 153 \ 120 & 173 & 140 & 180 \end{array}$

Accepted Answer

The answer of Construct a normal probability plot of the...

Question 18

Two random variables are normally distributed with the same mean. One has a standard deviation of 10 while the other has a standard deviation of 15. How will the graphs of the two variables differ and how will they be alike?

Accepted Answer

Both graphs will have the same shape (th

Question 19

Provide an appropriate response.
-When a normal probability plot is constructed, which axis is used for the normal scores (horizontal or vertical)?

Accepted Answer

The convention of the text is

Question 20

Use the empirical rule to solve the problem.
-The systolic blood pressure of 18-year-old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. What percentage of 18-year-old women have a
Systolic blood pressure between 96 mmHg and 144 mmHg?

Accepted Answer

A) 99.99% 
B) 68.26% 
C) 95.44% 
D) 99.74% 
A) 99.99% 
B) 68.26% 
C) 95.44% 
D) 99.74%

Use a table of areas to find the specified area under the standard normal curve. -The area that lies between -0.73 and 2.27

Find the indicated probability or percentage for the normally distributed variable. -The variable $X$ is normally distributed.The mean is $\mu = 22.0$ and the standard deviation is $\sigma = 2.4$ . Find $P ( 19.7 < X < 25.3 )$ .

Provide an appropriate response. Assume that the variable under consideration has a density curve. -The area under the density curve that lies to the right of 12 is 0.405. What percentage of all possible observations of the variable are at most 12?

Suppose that you know the area under the standard normal curve to the right of -2. How could you use this to find the area under the standard normal curve to the left of 2? Explain your reasoning.

Use a table of areas to obtain the shaded area under the standard normal curve. -

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to identify outliers, if any. Explain your reasoning.

Use the empirical rule to solve the problem. -The amount of Jen's monthly phone bill is normally distributed with a mean of $78 and a standard deviation of $8. Fill in the blanks. 68.26% of her phone bills are between $_ and $_.

A normal probability plot is given below for the weekly incomes (in dollars)of a sample of engineers in one town. Use the plot to assess the normality of the incomes of engineers in this town. Explain your reasoning.

For a variable with a density curve, what is the relationship between the percentage of all possible observations of the variable that lie within any specified range and the corresponding area under its density curve?

Use a table of areas to find the specified area under the standard normal curve. -The area that lies either to the left of 1.56 or to the right 2.30

A variable is normally distributed. 42% of the possible observations of the variable lie between 20 and 28. What information does this give you about the graph of the normal curve for this variable?

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution. -A product is manufactured in batches of 120 and the overall rate of defects is 5%. Estimate the probability that a randomly selected batch contains more than 6 defects.

Two random variables are normally distributed with the same mean. One has a standard deviation of 10 while the other has a standard deviation of 15. How will the graphs of the two variables differ and how will they be alike?

Provide an appropriate response. -When a normal probability plot is constructed, which axis is used for the normal scores (horizontal or vertical)?

Use the empirical rule to solve the problem. -The systolic blood pressure of 18-year-old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. What percentage of 18-year-old women have a Systolic blood pressure between 96 mmHg and 144 mmHg?

The Nature of Statistics

Organizing Data

Descriptive Measures

Probability Concepts

Discrete Random Variables

The Sampling Distribution of the Sample Mean

Confidence Intervals for One Population Mean

Hypothesis Tests for One Population Mean

Inferences for Two Population Means

Inferences for Population Standard Deviations

Inferences for Population Proportions

Chi-Square Procedures

Descriptive Methods in Regression and Correlation

Inferential Methods in Regression and Correlation

Analysis of Variance Anova

Filters

Exam 6: The Normal Distribution

Use a table of areas to find the specified area under the standard normal curve. -The area that lies between -0.73 and 2.27

Find the indicated probability or percentage for the normally distributed variable. -The variable XXX is normally distributed.The mean is μ=22.0\mu = 22.0μ=22.0 and the standard deviation is σ=2.4\sigma = 2.4σ=2.4 . Find P(19.7<X<25.3)P ( 19.7 < X < 25.3 )P(19.7<X<25.3) .

Provide an appropriate response. Assume that the variable under consideration has a density curve. -The area under the density curve that lies to the right of 12 is 0.405. What percentage of all possible observations of the variable are at most 12?

Suppose that you know the area under the standard normal curve to the right of -2. How could you use this to find the area under the standard normal curve to the left of 2? Explain your reasoning.

Use a table of areas to obtain the shaded area under the standard normal curve. -

A normal probability plot is given below for a sample of scores on an aptitude test. Use the plot to identify outliers, if any. Explain your reasoning.

Use the empirical rule to solve the problem. -The amount of Jen's monthly phone bill is normally distributed with a mean of $78 and a standard deviation of $8. Fill in the blanks. 68.26% of her phone bills are between $___ and $___.

A normal probability plot is given below for the weekly incomes (in dollars)of a sample of engineers in one town. Use the plot to assess the normality of the incomes of engineers in this town. Explain your reasoning.

For a variable with a density curve, what is the relationship between the percentage of all possible observations of the variable that lie within any specified range and the corresponding area under its density curve?

Use a table of areas to find the specified area under the standard normal curve. -The area that lies either to the left of 1.56 or to the right 2.30

A variable is normally distributed. 42% of the possible observations of the variable lie between 20 and 28. What information does this give you about the graph of the normal curve for this variable?

Estimate the indicated probability by using the normal distribution as an approximation to the binomial distribution. -A product is manufactured in batches of 120 and the overall rate of defects is 5%. Estimate the probability that a randomly selected batch contains more than 6 defects.

Construct a normal probability plot of the given data. -The prices per gallon (in dollars)of regular unleaded gasoline at twelve service stations are given below. 1.79 2.09 1.89 1.99 1.75 1.81 1.93 2.19 2.01 2.15 1.95 1.85

Construct a normal probability plot of the given data. -The systolic blood pressure (in mmHg)is given below for a sample of 12 men aged between 60 and 65. 127 135 118 164 143 130 125 153 120 173 140 180

Two random variables are normally distributed with the same mean. One has a standard deviation of 10 while the other has a standard deviation of 15. How will the graphs of the two variables differ and how will they be alike?

Provide an appropriate response. -When a normal probability plot is constructed, which axis is used for the normal scores (horizontal or vertical)?

Use the empirical rule to solve the problem. -The systolic blood pressure of 18-year-old women is normally distributed with a mean of 120 mmHg and a standard deviation of 12 mmHg. What percentage of 18-year-old women have a Systolic blood pressure between 96 mmHg and 144 mmHg?

The Nature of Statistics

Organizing Data

Descriptive Measures

Probability Concepts

Discrete Random Variables

The Sampling Distribution of the Sample Mean

Confidence Intervals for One Population Mean

Hypothesis Tests for One Population Mean

Inferences for Two Population Means

Inferences for Population Standard Deviations

Inferences for Population Proportions

Chi-Square Procedures

Descriptive Methods in Regression and Correlation

Inferential Methods in Regression and Correlation

Analysis of Variance Anova

Filters

Find the indicated probability or percentage for the normally distributed variable. -The variable $X$ is normally distributed.The mean is $\mu = 22.0$ and the standard deviation is $\sigma = 2.4$ . Find $P ( 19.7 < X < 25.3 )$ .

Use the empirical rule to solve the problem. -The amount of Jen's monthly phone bill is normally distributed with a mean of $78 and a standard deviation of $8. Fill in the blanks. 68.26% of her phone bills are between $_ and $_.