Intro to Stat Chapter 1 Review

A pharmaceutical company wants to conduct a survey of 30 individuals who have high cholesterol. The company has obtained a list from primary care physicians throughout the country of 5700 individuals who are known to have high cholesterol. Design a sampling method to obtain the individuals in the sample. Be sure to support the choice. What sampling​ method(s) is/are​ valid?

- Group the individuals by common primary care physician. Assign each physician a different number and use a random number table to select physicians until the total number of patients of all the selected physicians is at least 30. - Group the individuals by common primary care physician. For each​ group, assign all the individuals different​ numbers, and use a random number table to select an appropriate number of individuals. - Alphabetize the list of 5700 individuals by last name and select one of the first 190 individuals at random. Starting from the selected​ individual, read down the list and select every 190th individual.

A club wants to sponsor a panel discussion on the upcoming national election. The club wants four of its members to lead the panel discussion. Write a short description of the processes that can be used to generate your sample. Obtain a simple random sample of size 4 from the table. Which of the following would produce a simple random​ sample? Select all that apply.

- Number the names from 1 to 25 and use a random number generator to produce 4 different numbers corresponding to the names. - List each name on a separate piece of​ paper, place them all in a​ hat, and pick four.

A salesperson obtained a systematic sample of size 25 from a list of 500 clients. To do​ so, he randomly selected a number from 1 to 20​, obtaining the number 13. He included in the sample the 13th client on the list and every 20th client thereafter. List the numbers that correspond to the 25 clients selected.

13, 33, ..., 493 (Do this by (20*24)+13

Grouping together similar experimental units and then randomly assigning the experimental units within each group to a treatment is called:

Blocking

To determine customer opinion of their safety features​, Daimler minus Chrysler randomly selects 70 service centers during a certain week and surveys all customers visiting the service centers. What type of sampling is​ used?

Cluster

To help assess student learning in her music theory ​courses, a music professor at a community college implemented​ pre- and​ post-tests for her music theory students. A​ knowledge-gained score was obtained by taking the difference of the two test scores. What type of experimental design is​ this? What is the response variable in this​ experiment? What is the​ treatment?

Matched pair ; Difference in test scores ; Music theory course

An anti dash drunk driving advocate wants to estimate the percentage of people who favor increasing the penalty for drunk driving. She conducts a nationwide survey of 1360 randomly selected adults 18 years and older. The interviewer asks the​ respondents, ​"Do you favor harsher penalties for those convicted for drunk driving question mark​" Which of these best describes the bias in the​ survey? How can the bias be​ remedied?

Response bias ; The interviewer should reword the question.

Define statistics.

Statistics is the science of​ collecting, organizing,​ summarizing, and analyzing information to draw a conclusion and answer questions. In​ addition, statistics is about providing a measure of confidence in any conclusions.

To determine her body temperature​, Debra 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. What type of sampling is​ used?

Stratified

Researchers wanted to determine if there was an association between daily tea consumption and the occurrence of breast cancer. The researchers looked at 93 comma 524 women and asked them to report their tea​-drinking habits. The researchers also determined which of the women had IDC breast cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of green tea per day was associated with a reduction in IDC breast cancer. What is the explanatory​ variable?

The explanatory variable is whether the woman has IDC breast cancer or not. (The explanatory variable is consumption of green tea.?)

Researchers wanted to determine if there was an association between daily tea consumption and the occurrence of breast cancer. The researchers looked at 93 comma 524 women and asked them to report their tea​-drinking habits. The researchers also determined which of the women had IDC breast cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of green tea per day was associated with a reduction in IDC breast cancer. In their​ report, the researchers stated that​ "After adjusting for various demographic and lifestyle​ variables, daily consumption of six or more cups was associated with a​ 30% reduced prevalence of IDC breast cancer​." Why was it important to adjust for these​ variables?

The researchers may be concerned with confounding that occurs when the effects of two or more explanatory variables are not separated or when there are some explanatory variables that were not considered in a​ study, but that affect the value of the response variable.

Researchers wanted to determine if there was an association between the level of satisfaction of an individual and their risk of diabetes. The researchers studied 1622 people over the course of 5 years. During this 5​-year ​period, they interviewed the individuals and asked questions about their daily lives and the hassles they face. In​ addition, hypothetical scenarios were presented to determine how each individual would handle the situation. These interviews were videotaped and studied to assess the emotions of the individuals. The researchers also determined which individuals in the study experienced any type of diabetes over the 5​-year period. After their​ analysis, the researchers concluded that the satisfied individuals were less likely to experience diabetes. In the​ report, the researchers stated that​ "the research team also​ hasn't ruled out that a common factor like genetics could be causing both the emotions and the diabetes​." Explain what this sentence means.

The researchers may be concerned with confounding that occurs when the effects of two or more explanatory variables are not separated or when there are some explanatory variables that were not considered in a​ study, but that affect the value of the response variable.

Researchers wanted to determine if there was an association between the level of satisfaction of an individual and their risk of diabetes. The researchers studied 1622 people over the course of 5 years. During this 5​-year ​period, they interviewed the individuals and asked questions about their daily lives and the hassles they face. In​ addition, hypothetical scenarios were presented to determine how each individual would handle the situation. These interviews were videotaped and studied to assess the emotions of the individuals. The researchers also determined which individuals in the study experienced any type of diabetes over the 5​-year period. After their​ analysis, the researchers concluded that the satisfied individuals were less likely to experience diabetes. What is the response​ variable? What is the explanatory​ variable?

The response variable is 'whether or not diabetes was contracted,' because it 'is the variable of interest.' ; The explanatory variable is 'level of satisfaction,' because it 'affects the other variable.'

Researchers wanted to determine if there was an association between daily tea consumption and the occurrence of breast cancer. The researchers looked at 93 comma 524 women and asked them to report their tea​-drinking habits. The researchers also determined which of the women had IDC breast cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of green tea per day was associated with a reduction in IDC breast cancer. What is the response variable in the​ study? Is the response variable qualitative or​ quantitative?

The response variable is whether the woman has IDC breast cancer or not. The response variable is qualitative.

Upper A study is conducted to determine if there is a relationship between stomach cancer and alcohol consumption. Everyone treated at a hospital for stomach cancer was asked about their alcohol consumption. Does the description correspond to an observational study or an​ experiment?

The study is an observational study because the study examines individuals in a sample comma but does not try to influence the response variable.

Determine whether the underlined value is a parameter or a statistic. Following the election comma Modifying 18 % with underline of the governors of all 50 areas of a country were female. nothing nothing nothing Is the value a parameter or a​ statistic?

The value is a parameter because the governors of all 50 area of a country are a population.

Determine whether the underlined value is a parameter or a statistic. Following the election comma Modifying 18 % with underline of the governors of all 50 areas of a country were female. nothing nothing nothing Is the value a parameter or a​ statistic?

The value is a parameter because the governors of all 50 area of a country nothingare a population.

Volume of water in a swimming pool Is the variable discrete or​ continuous?

The variable is continuous because it is not countable.

Miles per hour at which a car is traveling Is the variable qualitative or​ quantitative?

The variable is quantitative because it is a numerical measure.

Researchers wanted to determine if there was an association between the level of satisfaction of an individual and their risk of diabetes. The researchers studied 1622 people over the course of 5 years. During this 5​-year ​period, they interviewed the individuals and asked questions about their daily lives and the hassles they face. In​ addition, hypothetical scenarios were presented to determine how each individual would handle the situation. These interviews were videotaped and studied to assess the emotions of the individuals. The researchers also determined which individuals in the study experienced any type of diabetes over the 5​-year period. After their​ analysis, the researchers concluded that the satisfied individuals were less likely to experience diabetes. What type of observational study was​ this? Explain.

This was a 'cohort study' because information was collected about a group of individuals 'by observing them over a long period of time.'

Researchers wanted to determine if there was an association between daily tea consumption and the occurrence of breast cancer. The researchers looked at 93 comma 524 women and asked them to report their tea​-drinking habits. The researchers also determined which of the women had IDC breast cancer. After their​ analysis, the researchers concluded that consumption of six or more cups of green tea per day was associated with a reduction in IDC breast cancer. What type of observational study was​ this? Explain.

This was a​ cross-sectional study because all information about the individuals was collected at a specific point in time.