QMB3250 Exam with correct answers
Determine if each of these types of data are categorical (ordinal), categorical (nominal), or
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quantitative by matching them with their correct descriptor. Answers can be used more than
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once. - ANSWER: ➡ Annual income of Florida residents - Quantitative
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Blood types of Florida residents - Categorical (nominal)
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Educational level of Florida residents - Categorical (ordinal) o o o o o o o
Ethnicity of Florida residents - Categorical (nominal)
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A researcher for McDonalds wanted to compare consumer opinions for the Big Mac in different
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countries, so he collected data from customers in Ireland, Mexico, and the USA. The data he
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collected from this study would be best described as? - ANSWER: ➡ Cross Sectional
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The average house price in Northwest Gainesville is $290,000 with a standard deviation of
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$35,500. Your parents decided to move to Gainesville to keep an eye on you and buy a house in
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Northwest Gainesville for 341,910. Find the z-score corresponding to your parent's brand
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new home. Round your answer to one decimal place. - ANSWER: ➡ 1.5 or 1.4623
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margin of error o o
z = (y - mu) / standard dev
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The contents of a lotion bottle follow a normal distribution with a mean of 18 fl oz and a
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standard deviation of 0.15 oz.
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What is the probability that the contents of a bottle are less than 17.8? (Enter the value to two
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decimal places.) Keep the value as given from JMP. Do not change to a percentage. - ANSWER:
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➡ 0.09 or 0.0912
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The city of Gainesville is trying to determine the average price for a gallon of gas. They
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randomly sampled 22 gas stations and found the sample mean to be $2.04 with a standard
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,deviation of $0.16. Assume that all of the assumptions are met. Calculate a 95% confidence
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interval for the population mean gas price in Gainesville. - ANSWER: ➡ (1.97, 2.11)
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For the given scenario, define the parameter of interest:
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Meteorologists randomly recorded the peak temperature for 20 different days in the summer o o o o o o o o o o o o
in Gainesville, FL. - ANSWER: ➡ mu = the population mean peak temperature in the summer
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in Gainesville, FL
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Your professor wants to construct a 95% confidence interval of the population mean exam 1
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score for QMB3250. She has over eight hundred students in the class. She randomly samples
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10 students scores, which are listed below:
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82, 78, 90, 76, 88, 24, 86, 80, 78, 84
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Which assumptions/conditions are violated, if any? - ANSWER: ➡ Nearly Normal Condition
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Macys takes a random sample of 10 customers to determine the average amount of money
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spent at the store in a single trip. Using the data collected, they calculated the 95% confidence
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interval as (59.02, 72.38).
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What conclusion can we make regarding this interval with 95% confidence? - ANSWER: ➡ We
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are 95% confident that the population mean amount spent at Macys during a single trip is
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between $59.02 and $72.38.
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An internet company wanted to determine what proportion of his website visitors found his
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site through Facebook Ads. The site receives about 10,000 unique visitors per month. In order
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to find out the answer to their question they randomly sampled 100 visitors to their site. The
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values they obtained were all independent from each other, and the expected number of who
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did and did not come to the site from a Facebook Ad is greater than 10.
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Can we assume a normal distribution for the sampling distribution of the sample proportion? -
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ANSWER: ➡ Yes
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Apple wanted to determine if the average iPhone user spent more than 3 hours on their phone
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per day. They surveyed 35 UF football players, all seniors. All responses were independent of
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one another.
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, Can we assume normal distribution of the sampling distribution of the sample mean? -
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ANSWER: ➡ No, the randomization condition was not met
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The United States government wanted to determine what proportion of Americans approve of
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the current president, so they conducted a survey of 200 randomly chosen Americans. Assume
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that the true proportion of Americans who approve of the current president is 0.52. Determine
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what the mean and the standard deviation of the sampling distribution of the sample
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proportion would be. Round to 2 decimal places when necessary.
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The mean of the sampling distribution is _____ and the standard deviation of the sampling
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distribution is _____ - ANSWER: ➡ 0.52, 0.04
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Tesla wanted to determine the average miles per kWh that their vehicles get across all models
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and variations. They took a sample of 100 of their vehicles and recorded the resulting data.
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Assume that the true population mean is 30 kWh and that the population standard deviation is
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3. Determine the correct mean and standard deviation for the sampling distribution of the
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sample mean.
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The mean is 30 and the standard deviation is 0.3 . - ANSWER: ➡ 30, 0.3
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A student is looking at a large data set and wants to determine if he should use either a
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confidence interval for the population proportion or a confidence interval for the population
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mean. The random and representative survey asked the question, "Have you seen the movie
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Avengers: Endgame?" The survey collected 3,000 responses from people all over the United
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States (population ~ 327 million at time of surveying). 1,200 people said "Yes", while the other
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1,800 respondents said "No."
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Should the student use a confidence interval for the population proportion or population
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mean? Choose the answer with the best explanation. - ANSWER: ➡ confidence interval for the
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population proportion because the data is categorical. Additionally, the sampling was random
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and representative, the check 10% condition is met, and there are at least 10 successes and 10
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failures.
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From the given scenario, define the population proportion.
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In 2019, a national survey organization asked the question "Do you go on more than two
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vacations per year?" to a random sample of 2,000 Americans. 580 responded "Yes", while the
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