Identify the type of observational study (cross-sectional,…
Identify the type of observational study (cross-sectional, retrospective, or prospective) described below. A research company uses a device to record the viewing habits of about 7500 households, and the data collected today will be used to determine the proportion of households tuned to a particular news program.
Read DetailsA simple random sample of n subjects is selected in such a w…
A simple random sample of n subjects is selected in such a way that every possible sample of the same size n has the same chance of being chosen. (A simple random sample is often called a random sample, but strictly speaking, a random sample has the weaker requirement that all members of the population have the same chance of being selected.) Determine whether each of the following is a simple random sample and a random sample. Complete parts a through c. a. In Major League Baseball, there are 30 teams, each with an active roster of 25 players. The names of the teams are printed on 30 separate index cards, the cards are shuffled, and one card is drawn. The sample consists of the 25 players on the active roster of the selected team. This sample [blank1] a simple random sample. It [blank2] a random sample. b. For the same Major League Baseball population described in part (a), the 750 names of the players are printed on 750 separate index cards, and the cards are shuffled. Twenty-five different cards are selected from the top. The sample consists of the 25 selected players. This sample [blank3] a simple random sample. It [blank4] a random sample. c. For the same Major League Baseball population described in part (a), a sample is constructed by selecting the 25 youngest players. This sample [blank5] a simple random sample. It [blank6] a random sample.
Read DetailsA student’s course grade is based on one midterm that count…
A student’s course grade is based on one midterm that counts as 10% of his final grade, one class project that counts as 10% of his final grade, a set of homework assignments that counts as 30% of his final grade, and a final exam that counts as 50% of his final grade. His midterm score is 76, his project score is 84, his homework score is 79, and his final exam score is 66. What is his overall final score? [blank1] What letter grade did he earn (A, B, C, D, or F)? Assume that a mean of 90 or above is an A, a mean of at least 80 but less than 90 is a B, and so on. [blank2]
Read DetailsIdentify which of these types of sampling is used: random,…
Identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster. To determine her body temperature, Jean divides up her day into three parts: morning, afternoon, and evening. She then measures her body temperature at 2 randomly selected times during each part of the day.
Read DetailsIdentify a major problem with the study. In a survey conduct…
Identify a major problem with the study. In a survey conducted by USA Today, 1465 Internet users chose to respond to this question posted on the USA Today electronic edition: “Is news online as satisfying as print and TV news?” 52% of the respondents said “yes.”
Read DetailsListed below are amounts (in millions of dollars) collecte…
Listed below are amounts (in millions of dollars) collected from parking meters by a security service company and other companies during similar time periods. Do the limited data listed here show evidence of stealing by the security service company’s employees? Security Service Company: 1.4 1.7 1.6 1.5 1.5 1.6 1.7 1.5 1.5 1.8 Other Companies: 1.7 1.9 1.6 1.8 1.7 1.8 1.6 1.7 1.8 1.7 Find the coefficient of variation for each of the two samples, then compare the variation. The coefficient of variation for the amount collected by the security service company is [ans1]%. (Round to one decimal place as needed.) The coefficient of variation for the amount collected by the other companies is [ans2]%. (Round to one decimal place as needed.) Do the limited data listed here show evidence of stealing by the security service company’s employees? Consider a difference of greater than 1% to be significant. Fill in your choice here [ans3] A. Yes. There is a significant difference in the variation. B. No. There is a not significant difference in the variation. C. Yes. There is a not significant difference in the variation. D. No. There is a significant difference in the variation.
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