Sta 2023 Test 1

STA 2023 TEST 1 A survey conducted among students in the school cafeteria asked a set of questions listed below. Which survey question would produce a qualitative response? How many servings of fruit do you eat each day? *What is your favorite dish? How many cups of fruit juice do you drink daily? How many hours do you spend reading books every day? CONCEPT Qualitative and Quantitative Data 2 The following shows the Consumer Price Index (CPI) for the years . All of the values use a reference year of 1983. Which of the following is true about the CPI, based on the information? $100 in 2001 would have been worth 189.70 in 1983. $100 in 2000 would be equivalent to $183.70 in 2003. $100 in 2005 would be equivalent to $194.50 in 1983. • $100 in 1983 would be equivalent to $172.40 in 2000. CONCEPT Index Number and Reference Value 3 A team of researchers want to measure the distance covered while driving compared to a car's driving speed. Which statement is correct? The speed of the car is a response variable. • The speed of the car is an explanatory variable. The speed of the car is a dependent variable. The speed of the car is a confounding variable. 4 Which of the following data types will be continuous? The number of children younger than ten that visited a planetarium last week • The total weight of apples harvested in the farm in a season The letter grades students received on a class quiz The number of cars in 100 households 5 A trainer is studying the effects of vitamin D on his athletes. He has realized that there are many potential confounding factors, such as gender and age. To limit the effect of these confounding variables, he decided to first group two athletes together based on these variables (for example, two 21-year-old males). Then he randomly assigned one person to receive the vitamin D and the other to receive a sugar pill. What type of experimental design does this situation demonstrate? • Matched-Pair Design Simple Random Design Completely Randomized Design Randomized Block Design 6 Of 400 randomly selected people in the city of Lyon, France, 60 people had the first name Hugo. Which of these does NOT represent inferential statistics? 15% of the people surveyed have the first name Hugo. 15% of the people who live in France have the first name Hugo. • 15% of the people who live in Europe have the first name Hugo. 15% of the people who live in Lyon have the first name Hugo. 7 Which of these random samples represents a representative sample of the number of students who enjoy science class? 30 students who received high grades in their science class last semester • 30 students in the lunchroom 30 students who failed science class last year 30 students who participated in the science fair 8 In 2007, 4% of people buying new cell phones purchased a bluetooth earpiece during the same transaction. In 2012, 28% of people buying new cell phones purchased a bluetooth earpiece during the same transaction. Of the following choices, what is correct about the growth of bluetooth sales? It rose by 12%. • It rose by 24 percentage points. It rose by 24%. It rose by 120 percentage points. 9 Nick designs a clinical trial to test a new anxiety medication by creating a control group and a treatment group. If he gives the medication to patients in the treatment group and not to the control group, some patients might find out that they're not being treated. To improve his study, Nick decides to give a sugar pill to the control group. The sugar pill is an example of a __________. case control confounding variable variable of interest • placebo 10 A poll conducted a week before the school election to the student council showed that Janice would win with 63% of the vote. The margin of error was 14%. If Janice needs to receive at least half the votes to win the election, can we be confident of Janice's victory? Yes, because she could receive as much as 77% of the vote. Yes, because the poll stated that she will win with 63% of the vote. • No, because she could receive as low as 49% of the vote. No, because she could receive as low as 14% of the vote. 11 The traffic volumes at a major intersection in New York were surveyed every day between one and four in the afternoon for a month to study the traffic patterns in the city. Which of the following types of bias affects the conclusions of the survey? Deliberate bias Non-response bias Response bias • Selection bias 12 A local bakery conducts a phone survey to find the most popular types of cakes. They selected 100 random phone numbers from the local telephone directory and called them. This type of sampling method is called __________. • Simple random sampling Multi-stage sampling Systematic random sampling Convenience sampling 13 Several scientific and statistical studies have been done to determine whether or not pollutants in soil increase the incidence of cancer. A study based on many previous studies summarizes that there is no link between pollutants in soil and cancer. This kind of statistical study is called a __________. Matched-pair design Clinical trial Prospective study • Retrospective study 14 An art teacher is trying to determine which class to offer next summer. She passes out a slip of paper to some of the students in the class asking them whether or not they liked her course, and what class they would most like to see offered in the summer. Which type of statistical study is the art teacher conducting? A census A single-blind study A double-blind study • A survey 15 It’s Saturday afternoon, and Denise is going shopping. She stops by a department store because she needs a new pair of shoes. She has picked out three styles that she likes. The store associate asks, “What is your shoe size?” Which type of question has the store associate asked? • Closed question Open question Open and binomial question Closed and binomial question 16 At a school of 900 students, 20% have blue eyes. A student randomly selects 100 students and finds 17% of them have blue eyes. A second student takes another random sample of 90 students and finds 24% of them have blue eyes. Which of the following explains why there is a difference between the two percentages? The sample sizes were both too small. Both samples suffered from non-response bias. The samples were not random samples. • Random error; the numbers were different due to variability inherent in sampling. 17 A shoe retailer decides to record the styles and sizes of shoes that his customers choose. He records this data for an entire year by keeping track of his customers' purchases. Which statement accurately describes the type of data the shoe retailer is collecting? The shoe retailer is receiving raw data on shoe sizes and styles from nearby shoe companies. The shoe retailer is gathering available data because customers tell him which shoe sizes and styles they prefer. • The shoe retailer is gathering raw data because he is recording shoe sizes and styles by himself. The shoe retailer is receiving available data on shoe sizes and styles from nearby shoe companies. 18 A different coffee seller offered to sell coffee to Jenae's company for half the cost of their current brand. Jenae knew her co-workers were really partial to the coffee they drank now, so she decided to conduct a study to see if they noticed the difference in flavor. Her co-workers were convinced they would. Jenae provided each person with a sample and said that some had the new coffee and some did not. Only Jenae knew who had which brand of coffee. Jenae's strategy is an example of a(n) ________. randomized experiment matched-pair designed experiment • blind experiment completely randomized experiment 19 Cindy measured and recorded the temperature of a liquid for an experiment. She used a poorly calibrated thermometer and noted the temperature as 100.5 degrees Fahrenheit. The actual temperature of the liquid was 95 degrees Fahrenheit. The percent error in her calculation is __________. -5.79% -4.08% • 5.79% 4.08% 20 A student group on a college campus wanted to create a survey about parking availability on campus. The student group randomly selected 300 students to take the survey. One of the questions read, “Many students believe the lack of available parking is a major problem. Do you agree or disagree?” Of the 300 students that took the survey, 285 surveys were returned. This survey will most likely suffer from which of the following types of bias? Non-response bias • Response bias There is no bias in the way this survey is carried out. Selection bias 21 Regan wants to study how reading on a computer affects comprehension among elementary school students. Regan thinks that girls and boys might differ and he also suspects that grade level will affect the results. He decides to create a male and a female group for each grade. Within each group, he randomly assigns half of the students to read an article on paper and half of the students to read the article on a computer. Which type of experimental design does this situation illustrate? Matched-Pair Completely Randomized Double-Blind • Randomized Block 22 Mike wants to find out the approximate income for professors in Michigan. He decides to randomly select 50 professors who work for a college or university in Michigan and obtain their salaries. What are the sample and the population of Mike's study? The professors in Michigan are the sample, and all the professors in the United States are the population. • The 50 professors that Mike interviews are his sample, and all of the professors who work in Michigan are the population. All of the professors who work in Michigan are the sample, and the 50 professors that Mike interviews are the population. The 50 professors that Mike interviews are his sample, and the professors that Mike does not interview are the population. 23 A local school newspaper's editor wants to survey students to determine the approval rating of the current student council president. How would the newspaper apply the cluster sampling method to find this information? The newspaper staff surveys 30 students from each grade in the school. The newspaper staff surveys random students from every grade in the school. • The newspaper staff surveys every student in a randomly selected grade. The newspaper staff surveys only the female students in the entire school. 24 A new pet food product for small dogs has been developed to help with tooth decay. Fifty-two dogs participate in the study. Each dog owner picks a card from a standard deck out of a hat. If the card is red, their dog will be in the treatment group. If the card is black, their dog will be in the placebo group. Which experimental design was used? Matched-Pair Design Case-Control Design Randomized Block Design • Completely Randomized Design 25 Jenae noticed that many of her co-workers would opt for the coffee that appeared to be most recently brewed, regardless of the flavor of the coffee offered. This leads her to believe that what she was witnessing was not really representative of everyone's true flavor preferences. She adapted her experimental study accordingly. Select one control in Jenae's experimental study. Jenae places condiments at random places throughout the kitchen. Jenae uses different locations in the kitchen for the coffee pots. • Jenae makes sure that the coffee in different pots is brewed at the same time. Jenae monitors the habits of the co-workers who do not drink coffee. 26 A study in which results are measured without intervention from the researcher is called a(n) __________. Simple random sample • Observational study Controlled experiment Pilot study 27 A factory manufactures motorcycles. One of its employees, working in the quality control department, checks the first 10 and the last 10 motorcycles manufactured in a day. This is what type of sampling? Stratified sampling • Convenience sampling Systematic sampling Voluntary response sampling 28 Rob sent an email survey to 2,000 cell phone owners asking about their satisfaction with their current plan. Only 256 people returned the survey and they were predominately 18-24 years old. Which of the following statements is true? Rob included too many people on the survey list, affecting the data collected. • The survey likely has bias because the people who could not answer differ from those who did answer. The survey suffers from census issues because only 256 people responded. Rob is ignoring the assumption that all survey participants will want to act independently. 29 A hunter is practicing his aim using a practice target. He takes 5 shots. All 5 shots hit the target, but they do not hit or surround the bullseye. In addition, all 5 shots are very spread apart on the target. Classify the hunter's accuracy and precision. Low accuracy and high precision High accuracy and high precision High accuracy and low precision • Low accuracy and low precision