QMB 3250 EXAM QUESTIONS WITH 100%
CORRECT SOLUTIONS!!
Determine if each of these types of data are categorical (ordinal), categorical (nominal), or
quantitative by matching them with their correct descriptor. Answers can be used more
than once.
Annual income of Florida residents - Quantitative
Blood types of Florida residents - Categorical (nominal)
Educational level of Florida residents - Categorical (ordinal)
Ethnicity of Florida residents - Categorical (nominal)
A researcher for McDonalds wanted to compare consumer opinions for the Big Mac in
different countries, so he collected data from customers in Ireland, Mexico, and the USA.
The data he collected from this study would be best described as?
Cross Sectional
The average house price in Northwest Gainesville is $290,000 with a standard deviation of
$35,500. Your parents decided to move to Gainesville to keep an eye on you and buy a
house in Northwest Gainesville for 341,910. Find the z-score corresponding to your
parent's brand new home. Round your answer to one decimal place.
1.5 or 1.4623
margin of error
z = (y - mu) / standard dev
,The contents of a lotion bottle follow a normal distribution with a mean of 18 fl oz and a
standard deviation of 0.15 oz.
What is the probability that the contents of a bottle are less than 17.8? (Enter the value to
two decimal places.) Keep the value as given from JMP. Do not change to a percentage.
0.09 or 0.0912
The city of Gainesville is trying to determine the average price for a gallon of gas. They
randomly sampled 22 gas stations and found the sample mean to be $2.04 with a standard
deviation of $0.16. Assume that all of the assumptions are met. Calculate a 95% confidence
interval for the population mean gas price in Gainesville.
(1.97, 2.11)
For the given scenario, define the parameter of interest:
Meteorologists randomly recorded the peak temperature for 20 different days in the
summer in Gainesville, FL.
mu = the population mean peak temperature in the summer in Gainesville, FL
Your professor wants to construct a 95% confidence interval of the population mean exam
1 score for QMB3250. She has over eight hundred students in the class. She randomly
samples 10 students scores, which are listed below:
82, 78, 90, 76, 88, 24, 86, 80, 78, 84
Which assumptions/conditions are violated, if any?
Nearly Normal Condition
,Macys takes a random sample of 10 customers to determine the average amount of money
spent at the store in a single trip. Using the data collected, they calculated the 95%
confidence interval as (59.02, 72.38).
What conclusion can we make regarding this interval with 95% confidence?
We are 95% confident that the population mean amount spent at Macys during a single trip is
between $59.02 and $72.38.
An internet company wanted to determine what proportion of his website visitors found his
site through Facebook Ads. The site receives about 10,000 unique visitors per month. In
order to find out the answer to their question they randomly sampled 100 visitors to their
site. The values they obtained were all independent from each other, and the expected
number of who did and did not come to the site from a Facebook Ad is greater than 10.
Can we assume a normal distribution for the sampling distribution of the sample
proportion?
Yes
Apple wanted to determine if the average iPhone user spent more than 3 hours on their
phone per day. They surveyed 35 UF football players, all seniors. All responses were
independent of one another.
Can we assume normal distribution of the sampling distribution of the sample mean?
No, the randomization condition was not met
The United States government wanted to determine what proportion of Americans approve
of the current president, so they conducted a survey of 200 randomly chosen Americans.
Assume that the true proportion of Americans who approve of the current president is
, 0.52. Determine what the mean and the standard deviation of the sampling distribution of
the sample proportion would be. Round to 2 decimal places when necessary.
The mean of the sampling distribution is _____ and the standard deviation of the sampling
distribution is _____
0.52, 0.04
Tesla wanted to determine the average miles per kWh that their vehicles get across all
models and variations. They took a sample of 100 of their vehicles and recorded the
resulting data. Assume that the true population mean is 30 kWh and that the population
standard deviation is 3. Determine the correct mean and standard deviation for the
sampling distribution of the sample mean.
The mean is 30 and the standard deviation is 0.3 .
30, 0.3
A student is looking at a large data set and wants to determine if he should use either a
confidence interval for the population proportion or a confidence interval for the
population mean. The random and representative survey asked the question, "Have you
seen the movie Avengers: Endgame?" The survey collected 3,000 responses from people all
over the United States (population ~ 327 million at time of surveying). 1,200 people said
"Yes", while the other 1,800 respondents said "No."
Should the student use a confidence interval for the population proportion or population
mean? Choose the answer with the best explanation.
CORRECT SOLUTIONS!!
Determine if each of these types of data are categorical (ordinal), categorical (nominal), or
quantitative by matching them with their correct descriptor. Answers can be used more
than once.
Annual income of Florida residents - Quantitative
Blood types of Florida residents - Categorical (nominal)
Educational level of Florida residents - Categorical (ordinal)
Ethnicity of Florida residents - Categorical (nominal)
A researcher for McDonalds wanted to compare consumer opinions for the Big Mac in
different countries, so he collected data from customers in Ireland, Mexico, and the USA.
The data he collected from this study would be best described as?
Cross Sectional
The average house price in Northwest Gainesville is $290,000 with a standard deviation of
$35,500. Your parents decided to move to Gainesville to keep an eye on you and buy a
house in Northwest Gainesville for 341,910. Find the z-score corresponding to your
parent's brand new home. Round your answer to one decimal place.
1.5 or 1.4623
margin of error
z = (y - mu) / standard dev
,The contents of a lotion bottle follow a normal distribution with a mean of 18 fl oz and a
standard deviation of 0.15 oz.
What is the probability that the contents of a bottle are less than 17.8? (Enter the value to
two decimal places.) Keep the value as given from JMP. Do not change to a percentage.
0.09 or 0.0912
The city of Gainesville is trying to determine the average price for a gallon of gas. They
randomly sampled 22 gas stations and found the sample mean to be $2.04 with a standard
deviation of $0.16. Assume that all of the assumptions are met. Calculate a 95% confidence
interval for the population mean gas price in Gainesville.
(1.97, 2.11)
For the given scenario, define the parameter of interest:
Meteorologists randomly recorded the peak temperature for 20 different days in the
summer in Gainesville, FL.
mu = the population mean peak temperature in the summer in Gainesville, FL
Your professor wants to construct a 95% confidence interval of the population mean exam
1 score for QMB3250. She has over eight hundred students in the class. She randomly
samples 10 students scores, which are listed below:
82, 78, 90, 76, 88, 24, 86, 80, 78, 84
Which assumptions/conditions are violated, if any?
Nearly Normal Condition
,Macys takes a random sample of 10 customers to determine the average amount of money
spent at the store in a single trip. Using the data collected, they calculated the 95%
confidence interval as (59.02, 72.38).
What conclusion can we make regarding this interval with 95% confidence?
We are 95% confident that the population mean amount spent at Macys during a single trip is
between $59.02 and $72.38.
An internet company wanted to determine what proportion of his website visitors found his
site through Facebook Ads. The site receives about 10,000 unique visitors per month. In
order to find out the answer to their question they randomly sampled 100 visitors to their
site. The values they obtained were all independent from each other, and the expected
number of who did and did not come to the site from a Facebook Ad is greater than 10.
Can we assume a normal distribution for the sampling distribution of the sample
proportion?
Yes
Apple wanted to determine if the average iPhone user spent more than 3 hours on their
phone per day. They surveyed 35 UF football players, all seniors. All responses were
independent of one another.
Can we assume normal distribution of the sampling distribution of the sample mean?
No, the randomization condition was not met
The United States government wanted to determine what proportion of Americans approve
of the current president, so they conducted a survey of 200 randomly chosen Americans.
Assume that the true proportion of Americans who approve of the current president is
, 0.52. Determine what the mean and the standard deviation of the sampling distribution of
the sample proportion would be. Round to 2 decimal places when necessary.
The mean of the sampling distribution is _____ and the standard deviation of the sampling
distribution is _____
0.52, 0.04
Tesla wanted to determine the average miles per kWh that their vehicles get across all
models and variations. They took a sample of 100 of their vehicles and recorded the
resulting data. Assume that the true population mean is 30 kWh and that the population
standard deviation is 3. Determine the correct mean and standard deviation for the
sampling distribution of the sample mean.
The mean is 30 and the standard deviation is 0.3 .
30, 0.3
A student is looking at a large data set and wants to determine if he should use either a
confidence interval for the population proportion or a confidence interval for the
population mean. The random and representative survey asked the question, "Have you
seen the movie Avengers: Endgame?" The survey collected 3,000 responses from people all
over the United States (population ~ 327 million at time of surveying). 1,200 people said
"Yes", while the other 1,800 respondents said "No."
Should the student use a confidence interval for the population proportion or population
mean? Choose the answer with the best explanation.
