SOPHIA STATISTICS UNIT 1 MILESTONE 1- PASSED

1 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 makes sure that the coffee in different pots is brewed at the same time. Jenae uses different locations in the kitchen for the coffee pots. Jenae monitors the habits of the co-workers who do not drink coffee. RATIONALE In an experiment, controls are when conditions are manipulated by the experimenter to keep conditions as consistent as possible. In this example Jenae brews coffee at the same time, so this is a control. CONCEPT Experimental Design I need help with this question SOPHIA STATISTICS UNIT 1 MILESTONE 1- PASS 2 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? Selection bias Deliberate bias Response bias Non-response bias RATIONALE Selection bias is when the mode of selection introduces a bias in the sample so that it is not representative of the population of interest. Since they only collected information from 1 to 4pm, this is a selection bias. CONCEPT Selection and Deliberate Bias I need help with this question 3 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? Case-Control Design Randomized Block Design Matched-Pair Design Completely Randomized Design RATIONALE Since all dogs are assigned treatment or control randomly by picking a card without considering other factors, this is called a completely randomized design. CONCEPT Completely Randomized Design I need help with this question 4 Sam counts how many people came to the local political meeting. He counts 72 people, but forgot about the 4 people sitting behind him. The percent error in his calculation is __________. -5.3% 50% -2.8% 5.6% RATIONALE Recall that the percent error is equivalent to the absolute difference divided by the actual value. If the actual number of people was 76, and the observed number of people was only 72, then the absolute error is: So we calculate the percentage error to be: CONCEPT Absolute Change and Relative Change I need help with this question 5 In a study to assess the risk of obesity with the amount of time exercised per week, researchers matched each patient, in a sample of 500 people who are obese, with a person of the same ethnicity, gender, and age (along with other similar characteristics) who is not obese. The researchers asked the patients and their matches a series of questions, and then tracked eating and exercise habits regularly for several years. Which type of statistical study are the researchers conducting? Prospective study Retrospective study Case-control study Designed experiment RATIONALE Since the study collected information on people over several years moving forward, it is a prospective study design. CONCEPT Prospective and Retrospective Studies I need help with this question 6 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 gathering raw data because he is recording shoe sizes and styles by himself. 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 receiving available data on shoe sizes and styles from nearby shoe companies. RATIONALE Since the retailer is gathering the data himself, this would be an example of raw data. CONCEPT Data I need help with this question 7 The manager of an amusement park conducts a survey among the people visiting the park to learn their favorite rides. Out of 100 people randomly selected to complete the survey, 25 people have chosen not to participate. The manager's survey suffers from which of the following types of bias? There is no bias in the way this survey is carried out. Nonresponse bias Selection bias Response bias RATIONALE Since 75% of the people didn't respond to the survey, we would worry about nonresponse bias, which means those who didn't respond would produce a very different outcome than those who did respond. CONCEPT Nonresponse and Response Bias I need help with this question 8 An insurance firm wants to estimate the percentage of senior citizens in a small town with approximately 2,534 residents. It asks a group of 85 randomly selected people in the town about their age. Select the statement that is TRUE. The sample is 85 people. The population is 2,534 people. None of the answer choices are true. The sample is 2,534 people. The population is 85 people. The sample is 85 people. The population is 2,449 people. RATIONALE Recall the entire set of interest is the population and a sample is a subset of that population. In this question the entire set is the 2534 residents, with the sample being the 85 that were chosen to be analyzed about their age. CONCEPT Sampling I need help with this question 9 Which of the following data types will be continuous? The number of children younger than ten that visited a planetarium last week The letter grades students received on a class quiz The number of cars in 100 households The total weight of apples harvested in the farm in a season RATIONALE The total weight of apples can take on any value and is therefore continuous. The other measures can only take on a limited number of values and are discrete. CONCEPT Discrete vs. Continuous Data I need help with this question 10 A study in which results are measured without intervention from the researcher is called a(n) __________. Pilot study Observational study Controlled experiment Simple random sample RATIONALE Recall that an observational study is one in which there is no control over the setting in any way. CONCEPT Observational Studies and Experiments I need help with this question 11 Choose the statement that accurately describes how a city government could apply systematic random sampling. Every resident is divided into groups, and 1,000 people are randomly selected to participate in a survey about city services. Every fifth person in a population is selected to participate in a survey about city services. Every resident in five neighborhoods is selected to participate in a survey about city services. Every individual over the age of 18 is selected to participate in a survey about city services. RATIONALE A systematic sample is when every nth element is chosen from the population. In this case, by choosing every 5th household, this makes is a systematic sample. CONCEPT Simple Random and Systematic Random Sampling I need help with this question 12 A pizza owner asked 50 customers to taste a new type of topping and found that 40 people liked its taste. Which of these is an example of descriptive statistics? 80% of all people like the taste of the pizza topping. 80% of the surveyed customers like the taste of the pizza topping. 80% of the people in the city where the pizza shop is located like the taste of the pizza topping. 80% of all the pizza shop's customers like the taste of the pizza topping. RATIONALE Recall a descriptive statistic is a summary figure which uses the sample information at hand. Using the sample information we know 40 of 50 people or 80% like the taste of the pizza topping. CONCEPT Statistics Overview I need help with this question 13 A researcher would like to determine which age groups (18-29, 30-49, 50-64, 65 or older) in the United States currently identify playing golf as their favorite pastime. Which statistical study would be most appropriate to answer this question? A prospective observational study A survey A census A single-blind experiment RATIONALE In order to obtain information about favorite pastimes, it would be best to solicit information from people directly by using a survey. CONCEPT Surveys I need help with this question 14 A scientist is conducting a study on the effect of eating chocolate and overall mood. They believe that gender is a significant factor. The participants are divided by gender. Then, within each group, participants are randomly assigned to consume either chocolate or a placebo and then rate their mood for the day. This experiment will run for two weeks. Which type of experimental design does this situation describe? Completely Randomized Design Matched-Pair Design Case-Control Design Randomized Block Design RATIONALE Since women are randomly assigned chocolate or placebo, this is a completely randomized design. CONCEPT Randomized Block Design I need help with this question