2
Business Statistics Exam 3 with precise detailed solutions || || || || || || ||
For a population that is not normally distributed, the distribution of the sample means will
|| || || || || || || || || || || || || || ||
________. - ✔✔approach a normal distribution
|| || || || ||
The size of the sampling error is ________. - ✔✔inversely related to the sample size—in
|| || || || || || || || || || || || || || ||
other words, the larger the sample size, the smaller the sampling error
|| || || || || || || || || || ||
The wildlife department has been feeding a special food to rainbow trout fingerlings in a
|| || || || || || || || || || || || || || ||
pond. Based on a large number of observations, the distribution of trout weights is normally
|| || || || || || || || || || || || || ||
distributed with a mean of 402.7 grams and a standard deviation of 8.8 grams. What is the
|| || || || || || || || || || || || || || || || ||
probability that the mean weight for a sample of 40 trout exceeds 405.5 grams? -
|| || || || || || || || || || || || || || || ||
✔✔0.0222
The mean of all possible sample means is equal to ____________. - ✔✔the population
|| || || || || || || || || || || || || ||
mean
What is the difference between a sample mean and the population mean called? -
|| || || || || || || || || || || || || ||
✔✔Sampling error ||
For a distribution of sample means constructed by sampling 5 items from a population of
|| || || || || || || || || || || || || || ||
15, ___________. - ✔✔there will be 3,003 possible sample means
|| || || || || || || || ||
For a given population with a normal probability distribution, the sampling distribution of XX
|| || || || || || || || || || || || ||
is a normal probability distribution for _________. - ✔✔any sample size
|| || || || || || || || || || ||
The tread life of tires mounted on light-duty trucks follows the normal probability
|| || || || || || || || || || || || ||
distribution with a population mean of 60,000 miles and a population standard deviation of
|| || || || || || || || || || || || || ||
,2
4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the
|| || || || || || || || || || || || || || || || ||
tread life. What is the likelihood of finding that the sample mean is between 59,050 and
|| || || || || || || || || || || || || || || ||
60,950? - ✔✔0.8664 || ||
A statewide sample survey is to be conducted. First, the state is subdivided into counties.
|| || || || || || || || || || || || || || ||
Seven counties are selected at random, and further sampling is concentrated on these seven
|| || || || || || || || || || || || ||
counties. What type of sampling is this? - ✔✔Cluster sampling
|| || || || || || || || || ||
The Office of Student Services at a large western state university maintains information on
|| || || || || || || || || || || || || ||
the study habits of its full-time students. Their studies indicate that the mean amount of
|| || || || || || || || || || || || || || ||
time undergraduate students study per week is 20 hours. The hours studied follows the
|| || || || || || || || || || || || || ||
normal distribution with a population standard deviation of six hours. Suppose we select a
|| || || || || || || || || || || || || ||
random sample of 144 current students. What is the standard error of the mean? - ✔✔0.50
|| || || || || || || || || || || || || || ||
Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers
|| || || || || || || || || || || ||
has maintained careful records regarding the time to prepare a return. The mean time to
|| || || || || || || || || || || || || || || ||
prepare a return is 90 minutes, and the population standard deviation of this distribution is
|| || || || || || || || || || || || || || ||
14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the
|| || || || || || || || || || || || || ||
preparation time. What is the probability that the mean time for the sample of 100 returns
|| || || || || || || || || || || || || || || ||
for this year is greater than 92? - ✔✔0.0764
|| || || || || || || ||
The weight of trucks traveling on a particular section of I-475 has a population mean of
|| || || || || || || || || || || || || || || ||
15.8 tons and a population standard deviation of 4.2 tons. What is the probability a state
|| || || || || || || || || || || || || || || ||
highway inspector could select a sample of 49 trucks and find the sample mean to be 14.3
|| || || || || || || || || || || || || || || || ||
tons or less? - ✔✔0.0062
|| || || ||
When all the items in a population have an equal chance of being selected for a sample,
|| || || || || || || || || || || || || || || || ||
the process is called _________________. - ✔✔simple random sampling
|| || || || || || || ||
The mean of all the sample means is _______. - ✔✔µ
|| || || || || || || || || ||
, 2
Suppose a research firm conducted a survey to determine the mean amount steady smokers
|| || || || || || || || || || || || ||
spend on cigarettes during a week. A sample of 100 steady smokers revealed that the
|| || || || || || || || || || || || || || || ||
sample mean is $20. The population standard deviation is $5. What is the probability that a
|| || || || || || || || || || || || || || || ||
sample of 100 steady smokers spend between $19 and $21? - ✔✔0.9544
|| || || || || || || || || || ||
A marketing firm is studying consumer preferences for winter fashions in four different
|| || || || || || || || || || || || ||
months. From a population of women 18 to 21 years of age, a random sample of 100
|| || || || || || || || || || || || || || || || ||
women was selected in January. Another random sample of 100 women was selected in
|| || || || || || || || || || || || || ||
March. Another random sample of 100 women was selected in June. Another random
|| || || || || || || || || || || || ||
sample of 100 women was selected in September. What is the number of samples? - ✔✔4
|| || || || || || || || || || || || || || ||
Sampling error is defined as _________. - ✔✔X − μ
|| || || || || || || || ||
Mileage tests were conducted on a randomly selected sample of 100 newly developed
|| || || || || || || || || || || || ||
automobile tires. The sample mean tread wear was 50,000 miles, with a population
|| || || || || || || || || || || || ||
standard deviation of 3,500 miles. What is the best estimate of the average tread life in
|| || || || || || || || || || || || || || || ||
miles for the entire population of these tires? - ✔✔50,000
|| || || || || || || || ||
The true sampling error is usually not known because ________. - ✔✔µ is unknown
|| || || || || || || || || || || || ||
Manufacturers were subdivided into groups by volume of sales. Those with more than $100
|| || || || || || || || || || || || || ||
million in sales were classified as large; those from $50 to $100 million as medium size; and
|| || || || || || || || || || || || || || || ||
those between $25 and $50 million, and so on. Samples were then selected from each of
|| || || || || || || || || || || || || || || || ||
these groups. What is this type of sampling called? - ✔✔Stratified random sampling
|| || || || || || || || || || || ||
The tread life of tires mounted on light-duty trucks follows the normal probability
|| || || || || || || || || || || || ||
distribution with a population mean of 60,000 miles and a population standard deviation of
|| || || || || || || || || || || || || ||
4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the
|| || || || || || || || || || || || || || || || ||
tread life. What is the standard error of the mean? - ✔✔632.46
|| || || || || || || || || || ||
The Office of Student Services at a large western state university maintains information on
|| || || || || || || || || || || || || ||
the study habits of its full-time students. Their studies indicate that the mean amount of
|| || || || || || || || || || || || || || ||
Business Statistics Exam 3 with precise detailed solutions || || || || || || ||
For a population that is not normally distributed, the distribution of the sample means will
|| || || || || || || || || || || || || || ||
________. - ✔✔approach a normal distribution
|| || || || ||
The size of the sampling error is ________. - ✔✔inversely related to the sample size—in
|| || || || || || || || || || || || || || ||
other words, the larger the sample size, the smaller the sampling error
|| || || || || || || || || || ||
The wildlife department has been feeding a special food to rainbow trout fingerlings in a
|| || || || || || || || || || || || || || ||
pond. Based on a large number of observations, the distribution of trout weights is normally
|| || || || || || || || || || || || || ||
distributed with a mean of 402.7 grams and a standard deviation of 8.8 grams. What is the
|| || || || || || || || || || || || || || || || ||
probability that the mean weight for a sample of 40 trout exceeds 405.5 grams? -
|| || || || || || || || || || || || || || || ||
✔✔0.0222
The mean of all possible sample means is equal to ____________. - ✔✔the population
|| || || || || || || || || || || || || ||
mean
What is the difference between a sample mean and the population mean called? -
|| || || || || || || || || || || || || ||
✔✔Sampling error ||
For a distribution of sample means constructed by sampling 5 items from a population of
|| || || || || || || || || || || || || || ||
15, ___________. - ✔✔there will be 3,003 possible sample means
|| || || || || || || || ||
For a given population with a normal probability distribution, the sampling distribution of XX
|| || || || || || || || || || || || ||
is a normal probability distribution for _________. - ✔✔any sample size
|| || || || || || || || || || ||
The tread life of tires mounted on light-duty trucks follows the normal probability
|| || || || || || || || || || || || ||
distribution with a population mean of 60,000 miles and a population standard deviation of
|| || || || || || || || || || || || || ||
,2
4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the
|| || || || || || || || || || || || || || || || ||
tread life. What is the likelihood of finding that the sample mean is between 59,050 and
|| || || || || || || || || || || || || || || ||
60,950? - ✔✔0.8664 || ||
A statewide sample survey is to be conducted. First, the state is subdivided into counties.
|| || || || || || || || || || || || || || ||
Seven counties are selected at random, and further sampling is concentrated on these seven
|| || || || || || || || || || || || ||
counties. What type of sampling is this? - ✔✔Cluster sampling
|| || || || || || || || || ||
The Office of Student Services at a large western state university maintains information on
|| || || || || || || || || || || || || ||
the study habits of its full-time students. Their studies indicate that the mean amount of
|| || || || || || || || || || || || || || ||
time undergraduate students study per week is 20 hours. The hours studied follows the
|| || || || || || || || || || || || || ||
normal distribution with a population standard deviation of six hours. Suppose we select a
|| || || || || || || || || || || || || ||
random sample of 144 current students. What is the standard error of the mean? - ✔✔0.50
|| || || || || || || || || || || || || || ||
Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers
|| || || || || || || || || || || ||
has maintained careful records regarding the time to prepare a return. The mean time to
|| || || || || || || || || || || || || || || ||
prepare a return is 90 minutes, and the population standard deviation of this distribution is
|| || || || || || || || || || || || || || ||
14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the
|| || || || || || || || || || || || || ||
preparation time. What is the probability that the mean time for the sample of 100 returns
|| || || || || || || || || || || || || || || ||
for this year is greater than 92? - ✔✔0.0764
|| || || || || || || ||
The weight of trucks traveling on a particular section of I-475 has a population mean of
|| || || || || || || || || || || || || || || ||
15.8 tons and a population standard deviation of 4.2 tons. What is the probability a state
|| || || || || || || || || || || || || || || ||
highway inspector could select a sample of 49 trucks and find the sample mean to be 14.3
|| || || || || || || || || || || || || || || || ||
tons or less? - ✔✔0.0062
|| || || ||
When all the items in a population have an equal chance of being selected for a sample,
|| || || || || || || || || || || || || || || || ||
the process is called _________________. - ✔✔simple random sampling
|| || || || || || || ||
The mean of all the sample means is _______. - ✔✔µ
|| || || || || || || || || ||
, 2
Suppose a research firm conducted a survey to determine the mean amount steady smokers
|| || || || || || || || || || || || ||
spend on cigarettes during a week. A sample of 100 steady smokers revealed that the
|| || || || || || || || || || || || || || || ||
sample mean is $20. The population standard deviation is $5. What is the probability that a
|| || || || || || || || || || || || || || || ||
sample of 100 steady smokers spend between $19 and $21? - ✔✔0.9544
|| || || || || || || || || || ||
A marketing firm is studying consumer preferences for winter fashions in four different
|| || || || || || || || || || || || ||
months. From a population of women 18 to 21 years of age, a random sample of 100
|| || || || || || || || || || || || || || || || ||
women was selected in January. Another random sample of 100 women was selected in
|| || || || || || || || || || || || || ||
March. Another random sample of 100 women was selected in June. Another random
|| || || || || || || || || || || || ||
sample of 100 women was selected in September. What is the number of samples? - ✔✔4
|| || || || || || || || || || || || || || ||
Sampling error is defined as _________. - ✔✔X − μ
|| || || || || || || || ||
Mileage tests were conducted on a randomly selected sample of 100 newly developed
|| || || || || || || || || || || || ||
automobile tires. The sample mean tread wear was 50,000 miles, with a population
|| || || || || || || || || || || || ||
standard deviation of 3,500 miles. What is the best estimate of the average tread life in
|| || || || || || || || || || || || || || || ||
miles for the entire population of these tires? - ✔✔50,000
|| || || || || || || || ||
The true sampling error is usually not known because ________. - ✔✔µ is unknown
|| || || || || || || || || || || || ||
Manufacturers were subdivided into groups by volume of sales. Those with more than $100
|| || || || || || || || || || || || || ||
million in sales were classified as large; those from $50 to $100 million as medium size; and
|| || || || || || || || || || || || || || || ||
those between $25 and $50 million, and so on. Samples were then selected from each of
|| || || || || || || || || || || || || || || || ||
these groups. What is this type of sampling called? - ✔✔Stratified random sampling
|| || || || || || || || || || || ||
The tread life of tires mounted on light-duty trucks follows the normal probability
|| || || || || || || || || || || || ||
distribution with a population mean of 60,000 miles and a population standard deviation of
|| || || || || || || || || || || || || ||
4,000 miles. Suppose we select a sample of 40 tires and use a simulator to determine the
|| || || || || || || || || || || || || || || || ||
tread life. What is the standard error of the mean? - ✔✔632.46
|| || || || || || || || || || ||
The Office of Student Services at a large western state university maintains information on
|| || || || || || || || || || || || || ||
the study habits of its full-time students. Their studies indicate that the mean amount of
|| || || || || || || || || || || || || || ||
