QMB 3250 Exam 1 UPDATED
QUESTIONS AND CORRECT ANSWERS
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. -
CORRECT ANSWER 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? - CORRECT ANSWER 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. - CORRECT ANSWER 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. - CORRECT
ANSWER 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. - CORRECT ANSWER (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. - CORRECT ANSWER 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? - CORRECT ANSWER 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? - CORRECT
ANSWER 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? -
CORRECT ANSWER 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? - CORRECT
ANSWER 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 _____ - CORRECT ANSWER 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 . - CORRECT ANSWER 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 ANSWER confidence interval for
the population proportion because the data is categorical. Additionally, the sampling was random and
representative, the check 10% condition is met, and there are at least 10 successes and 10 failures.
From the given scenario, define the population proportion.
In 2019, a national survey organization asked the question "Do you go on more than two vacations per
year?" to a random sample of 2,000 Americans. 580 responded "Yes", while the other 1,420 people
responded "No". - CORRECT ANSWER the proportion of all Americans who go on more than
two vacations per year
Population proportion = p
Entire group that we do not have all the data for
Given the following scenario, select the correct answer choice which that lists (1) if the necessary
assumptions for a confidence interval for population proportion are met and (2) what the correct
conditions are.
A student wants to determine what proportion of business majors study in Heavener during the school
week. Roughly, 1000 business degrees are confirmed each year. He asks the following question to 25
randomly selected UF business majors, "Do you study in Heavener at least once during the week?" Of
the 25 responses, 14 said "Yes" while 11 said "No". - CORRECT ANSWER Conditions are met.
Randomization, 10% Condition, and Success/Failure Condition are all met.
QUESTIONS AND CORRECT ANSWERS
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. -
CORRECT ANSWER 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? - CORRECT ANSWER 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. - CORRECT ANSWER 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. - CORRECT
ANSWER 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. - CORRECT ANSWER (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. - CORRECT ANSWER 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? - CORRECT ANSWER 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? - CORRECT
ANSWER 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? -
CORRECT ANSWER 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? - CORRECT
ANSWER 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 _____ - CORRECT ANSWER 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 . - CORRECT ANSWER 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 ANSWER confidence interval for
the population proportion because the data is categorical. Additionally, the sampling was random and
representative, the check 10% condition is met, and there are at least 10 successes and 10 failures.
From the given scenario, define the population proportion.
In 2019, a national survey organization asked the question "Do you go on more than two vacations per
year?" to a random sample of 2,000 Americans. 580 responded "Yes", while the other 1,420 people
responded "No". - CORRECT ANSWER the proportion of all Americans who go on more than
two vacations per year
Population proportion = p
Entire group that we do not have all the data for
Given the following scenario, select the correct answer choice which that lists (1) if the necessary
assumptions for a confidence interval for population proportion are met and (2) what the correct
conditions are.
A student wants to determine what proportion of business majors study in Heavener during the school
week. Roughly, 1000 business degrees are confirmed each year. He asks the following question to 25
randomly selected UF business majors, "Do you study in Heavener at least once during the week?" Of
the 25 responses, 14 said "Yes" while 11 said "No". - CORRECT ANSWER Conditions are met.
Randomization, 10% Condition, and Success/Failure Condition are all met.
