UCF QMB 3200 Final Exam Updated 2024/2025 Actual Questions and answers with complete solutions

A company wants to identify which of the two production methods has the smaller completion time. One sample of workers is selected and each worker first uses one method and then uses the other method. The sampling procedure being used to collect completion time data is based on - Matched samples. A doctor would like to know if men and women got the same amount of sleep per night or if women tended to get less sleep than men. He took a random sample of 100 of his male and 100 of his female patients and asked them how many hours of sleep they got, per night, on average. The women slept an average of 6.75 hours and the men slept an average of 7.5 hours. Suppose we also knew the population standard deviations to be 1.25 hours and 1.5 hours for men and women, respectively. Formulate the null and alternative hypotheses to test whether women sleep less than men do, on average - H0:: UmUm=0, Ha: Um-UW<0 A fast food restaurant has automatic drink dispensers to help fill orders more quickly. When the 12 ounce button is pressed, they would like for exactly 12 ounces of beverage to be dispensed. There is, however, undoubtedly some variation in this amount. The company does not want the machine to systematically over fill or under fill the cups. Which of the following gives the correct set of hypotheses? - H0: u=12, Ha: u not=12 A forecast model of the form is called a(n) - Quadratic trend equation. A graph of the standardized residuals plotted against values of the normal scores that helps to determine whether the assumption that the error term has a normal probability distribution appears to be valid is called a - Normal probability plot A local entrepreneur would like to know if those who live in a rural community are more likely to buy a real Christmas tree than those who live in an urban community. He takes a random sample of 100 people who reside in the city and a separate random sample of 100 people who live in the country and asks them if they buy a real tree at Christmas time. Of the urban participants, 22 buy a real tree. Of the rural participants, 28 buy a real tree. Let P1= the proportion of all people who live in rural communities and buy a real Christmas tree, and let P2 = the proportion of all people who live in urban communities and buy a real Christmas tree. State the null and alternative hypotheses. - H0: p1-p2<0, Ha:p1-p2>0A model in the form of , where each independent variable zj (for j = 1, 2,..., p) is a function of x1, x2,..., xk, is known as the: - general linear model. A news reporter states that the average number of temperature in January has never dropped below 10 degrees Fahrenheit. You go online to research this claim. The appropriate hypotheses are - H0: u>10, Ha: u<10. A positive forecast error indicates that the forecasting method _____ the dependent variable. - Underestimated. A researcher recruits 25 people to participate in a study on alcohol consumption and its interactions with Tylenol. The 25 participants had to come to a check-in center every day at 7:00 a.m. for one week. They were given various amounts of alcohol. Each day, each participant would flip a coin to determine if they also took Tylenol with their alcohol. They found that their BAC was 25% higher on days when they were given Tylenol with their alcohol than when they drank alcohol alone. This is an example of a(n) - matched sample design. A sample of 92 observations is taken from an infinite population. The sampling distribution of is approximately - normal because of the central limit theorem. A seasonal pattern: - occurs when a time series plot exhibits a repeating pattern over successive periods. A simple random sample of size n from an infinite population is a sample selected such that - each element is selected independently and is selected from the same population A simple random sample of size n from an infinite population of size N is to be selected. Each possible sample should have - the same probability of being selected A statistics teacher started class one day by drawing the names of 10 students out of a hat and asked them to do as many pushups as they could. The 10 randomly selected students averaged 15 pushups per person with a standard deviation of 9 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal. Which of the following statements is true? - A t distribution should be used because σ is unknown.A student wants to determine if pennies are really fair, meaning equally likely to land heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads up. What are the appropriate null and alternative hypotheses? - H0: p=.5, Ha:p not =.5. A time series from which the effect of season has been removed by dividing each original time series observation by the corresponding seasonal index is called a: - deseasonalized time series.