Exam 1 Review biostats

What is the first number in the five-number summary for the wrong-patient lawsuit data? (Give a number, rounded to the nearest cent.)

0

Redbox is an increasingly popular way to rent movies in the US. Individuals can go to a Redbox kiosk and have a wide variety of movies to choose from. A study was done in which researchers observed the duration of time (in seconds) individuals spent making a decision on which movie to rent at a Redbox. 800 700 - 600 I 500 I 400 I 300 I 200 I 100 [-----] 0 I - What is the longest observed time of the Redbox customers in this study? (Give an estimated number in seconds.)

710

What is the 75th percentile of the recorded study times? 2 4 8 10 12 This cannot be determined from the boxplot

8

Hepatic angiosarcoma is a rare and usually fatal type of liver cancer. (Ref 1). A study was conducted on four individuals with this illness. The data represent their survival times, in months. Survival times (months) 5 19 1 3 (Ref 1) Source: Biomedcentral Gastroenterology [Column 1][Column 2][Column 3] [Observered Data][Deviations from the Mean][Squared Deviations from the Mean] [x][x-X][(x-X)^2] [5][][] [19]["A"][] [1][]["B"=] [3][][] Give the number that would be entered into the space labeled "A" in the table above.

12

Redbox is an increasingly popular way to rent movies in the US. Individuals can go to a Redbox kiosk and have a wide variety of movies to choose from. A study was done in which researchers observed the duration of time (in seconds) individuals spent making a decision on which movie to rent at a Redbox. 800 700 - 600 I 500 I 400 I 300 I 200 I 100 [-----] 0 I - What is the 3rd Quartile of the Redbox decision times? (Give an estimated number.)

190

Hepatic angiosarcoma is a rare and usually fatal type of liver cancer. (Ref 1). A study was conducted on four individuals with this illness. The data represent their survival times, in months. Survival times (months) 5 19 1 3 (Ref 1) Source: Biomedcentral Gastroenterology [Column 1][Column 2][Column 3] [Observered Data][Deviations from the Mean][Squared Deviations from the Mean] [x][x-X][(x-X)^2] [5][][] [19]["A"][] [1][]["B"=] [3][][] Give the number that would be entered into the space labeled "B" in the table above.

36

What is the second number in the five-number summary for the wrong-patient lawsuit data? (Give a number, rounded to the nearest cent.)

3900

Hepatic angiosarcoma is a rare and usually fatal type of liver cancer. (Ref 1). A study was conducted on four individuals with this illness. The data represent their survival times, in months. Survival times (months) 5 19 1 3 (Ref 1) Source: Biomedcentral Gastroenterology What is the median survival time (in months)?

4

What is the fourth number in the five-number summary for the wrong-patient lawsuit data? (Give a number, rounded to the nearest cent.)

50145.5

On rare occasions, a medical procedure is performed on the wrong body part of a patient's body or on the wrong patient. These are called wrong-site and wrong-patient mistakes. Such errors occur hundreds of times each year across the United States. The medical community is trying to eliminate these errors but have had difficulty reducing their frequency. In a small percentage of these cases, the patient files a lawsuit against the hospital. Philip Stahel et al. conducted a study on these mistakes and the lawsuits that follow. (1) The data in the file WrongSiteWrongPatient.xlsx (located in the data page of the online text book.) represent the amount (in US dollars) hospitals have been required to pay in wrong-site and wrong-patient lawsuits. Some of the values equal zero, indicating that the hospital won the legal battle. (1) Source: JAMA Surgery Find the median amount hospitals had to pay in wrong-site lawsuits.

68,552

Hepatic angiosarcoma is a rare and usually fatal type of liver cancer. (Ref 1). A study was conducted on four individuals with this illness. The data represent their survival times, in months. Survival times (months) 5 19 1 3 (Ref 1) Source: Biomedcentral Gastroenterology What is the mean survival time (in months) for these 4 patients?

7

On rare occasions, a medical procedure is performed on the wrong body part of a patient's body or on the wrong patient. These are called wrong-site and wrong-patient mistakes. Such errors occur hundreds of times each year across the United States. The medical community is trying to eliminate these errors but have had difficulty reducing their frequency. In a small percentage of these cases, the patient files a lawsuit against the hospital. Philip Stahel et al. conducted a study on these mistakes and the lawsuits that follow. (1) The data in the file WrongSiteWrongPatient.xlsx (located in the data page of the online text book.) represent the amount (in US dollars) hospitals have been required to pay in wrong-site and wrong-patient lawsuits. Some of the values equal zero, indicating that the hospital won the legal battle. (1) Source: JAMA Surgery Find the standard deviation of the amount paid in wrong-site lawsuits. Round your answer to the nearest whole dollar. 71,404

71,404

Hepatic angiosarcoma is a rare and usually fatal type of liver cancer. (Ref 1). A study was conducted on four individuals with this illness. The data represent their survival times, in months. Survival times (months) 5 19 1 3 (Ref 1) Source: Biomedcentral Gastroenterology [Column 1][Column 2][Column 3] [Observered Data][Deviations from the Mean][Squared Deviations from the Mean] [x][x-X][(x-X)^2] [5][][] [19]["A"][] [1][]["B"=] [3][][] What is the standard deviation of the survival times? (Give your answer in months rounded to the nearest tenth.)

8.2

On rare occasions, a medical procedure is performed on the wrong body part of a patient's body or on the wrong patient. These are called wrong-site and wrong-patient mistakes. Such errors occur hundreds of times each year across the United States. The medical community is trying to eliminate these errors but have had difficulty reducing their frequency. In a small percentage of these cases, the patient files a lawsuit against the hospital. Philip Stahel et al. conducted a study on these mistakes and the lawsuits that follow. (1) The data in the file WrongSiteWrongPatient.xlsx (located in the data page of the online text book.) represent the amount (in US dollars) hospitals have been required to pay in wrong-site and wrong-patient lawsuits. Some of the values equal zero, indicating that the hospital won the legal battle. (1) Source: JAMA Surgery Find the mean amount hospitals had to pay in wrong-site lawsuits. Round your answer to the nearest whole dollar.

80,041

Which of the following studies depicts an observational study? A parent group examines 25 recently released PG-13 movies and records the number of sexual innuendos and curse words that occur in each. A sample of 504 patients in early stages of Alzheimer's disease is divided into two groups. One group receives an experimental drug and the other a placebo. The advance of the disease is tracked at one-month intervals over the next year.

A parent group examines 25 recently released PG-13 movies and records the number of sexual innuendos and curse words that occur in each.

Each presidential election, many different groups want to know how popular each candidate is among the electorate. In the recent election, one marketing research firm was asked by a special interest group to help estimate the proportion of Americans who supported a particular candidate. From a list of all registered voters, 8000 names were randomly selected. An automated phone-call was made to each of the 8000 individuals selected asking them to answer a few questions indicating their voting preferences. The marketing firm received 2969 responses. The population for this study was: All registered voters in the US The 2969 people who answered the survey questions The 8000 people who received a phone call

All registered voters in the US

Is the study described in the previous question an experiment or an observational study, and why? An experiment, because the students had control over which sampling method they used An experiment, because the students had control over which cereals would be selected for the study An observational study, because the students had no control over the price of the individual cereals An observational study, because the students had no control over which cereals were selected

An observational study, because the students had no control over the price of the individual cereals

Which of the following would be considered an experimental design? A Telephone Poll asking people about whether or not they vaccinate their children Administering the tuberculosis vaccination to one group and giving a placebo to another A census A mailed survey asking people whether or not they received the tuberculosis vaccine

Administering the tuberculosis vaccination to one group and giving a placebo to another

Studies have shown that retention of classroom materials can drop as low as 58% within 15 minutes of class and within 44% after the first hour after class. This forgetting curve continues so that within six days only 25% is remembered. How can a student conquer this forgetting curve? The researchers in this study claim that constant review is important. Suppose your teacher wanted to test this and invited you to participate in a study where you were asked to review specific material 15 minutes after class for 10 minutes, an hour after class for ten minutes and then again two days after class for 10 minutes. After the sixth day, your teacher asks you if you feel confident that you have retained at least 50% of the material. He then records your response as Yes, No, Not Sure. What type of data is your teacher collecting? Quantitative Categorical

Categorical

Studies have shown that retention of classroom materials can drop as low as 58% within 15 minutes of class and within 44% after the first hour after class. This forgetting curve continues so that within six days only 25% is remembered. How can a student conquer this forgetting curve? The researchers in this study claim that constant review is important. Suppose your teacher wanted to test this and invited you to participate in a study where you were asked to review specific material 15 minutes after class for 10 minutes, an hour after class for ten minutes and then again two days after class for 10 minutes. Your teacher also selects a group to give no review to the material over the six days. This group is called the: Hypothesis Group Treatment Group Population Group Control group

Control group

A researcher has collected the results of a survey where the participants were asked how many hours of T.V. they watch each day. The researcher tallies the frequencies for each category and computes mean number of hours watched. She then creates a histogram to help illustrate the overall distribution. Which of the five steps of the statistical process did the researcher apply? Design the Study Collect Data Describe the Data Make Inferences Take Action

Describe the Data

Researchers would like to determine if reviewing material consistently within an hour after class helps students perform better on exams than if students wait to review material the day before the exam. To answer this question the researchers are trying to determine if an observational study or an experiment would be more appropriate. They are discussing who the population would be and how they will determine which sampling method will best represent the population. Which of the five steps of the statistical process are the researchers currently applying? Design the Study Collect Data Describe the Data Make Inferences Take Action

Design the Study

In 1992, the U.S. government supported a study (that was run for 15 years) where 4608 low-income families were given a chance to move to less impoverished areas. They distributed vouchers and provided various support systems. The researchers wanted to determine if getting people out of poor neighborhoods would reduce the poverty level of U.S. citizens. The low-income families were randomly assigned to one of the following three groups. (1) the MTO LOW POVERTY VOUCHER (LPV) GROUP, which received Section 8 certificates or vouchers usable only in low-poverty areas (areas with less than 10 percent of the population below the poverty line in 1990), along with counseling and assistance in finding a private unit to lease; (2) the TRADITIONAL VOUCHER GROUP, which received regular Section 8 certificates or vouchers (geographically unrestricted) and ordinary briefings and assistance from the PHAs (Local Public Housing Authorities). (3) the CONTROL GROUP, which received no certificates or vouchers but remained eligible for public or project-based housing and other social programs to which families would otherwise have been entitled. This study was a/an: Observational study Experiment Neither

Experiment

Which one of the following histograms was made from data that are definitely skewed right?

I I I II II III IIII IIIIIII IIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIII

ages of students on the BYU-Idaho campus. They collected data from a random sample of n = 100 students. The sample mean was 21.2 and the sample standard deviation was 2.61. An excerpt of their data is given below. ID GENDER AGE 1 Female 21 2 Male 18 3 Male 12 4 Female 20 : : : 99 Male 25 The group notices an error in their data. The age of one of the males (ID=3) was entered incorrectly. He is actually 21 years old. When the error is corrected, what will happen to the sample median? The median will increase. The median will decrease. The median will stay the same. It is not possible to determine this without the full data set.

It is not possible to determine this without the full data set.

In a study to determine the average age of students at BYU-Idaho, which of the following would be the best sample? A simple random sample of students in the Crossroads during lunch All of the students living in one of the dorms on campus Many randomly selected students from each apartment building in Rexburg All the male students

Many randomly selected students from each apartment building in Rexburg

Test scores were recorded for students in a statistics class. The scores for the first test had a standard deviation of 3.8 points. The scores from the second test had a standard deviation of 4.8 points. Choose the correct statement below. The average test grade rose by 1 point The scores of the second test were closer together than the first The higher standard deviation of the second test indicates higher average scores on the second test than on the first None of the above are true

None of the above are true

Studies have shown that retention of classroom materials can drop as low as 58% within 15 minutes of class and within 44% after the first hour after class. This forgetting curve continues so that within six days only 25% is remembered. How can a student conquer this forgetting curve? The researchers in this study claim that constant review is important. Suppose your teacher wanted to test this and invited you to participate in a study where you were asked to review specific material 15 minutes after class for 10 minutes, an hour after class for ten minutes and then again two days after class for 10 minutes. Your teacher then gives you a short ten question quiz where your score out of ten is recorded. What type of data is your teacher collecting? Quantitative Categorical

Quantitative

Which one of the following is a statistically valid reason for sampling randomly when choosing subjects for a study? Correct Response Sampling randomly tends to reduce sampling bias or risk Sampling randomly (with a large sample) gives a perfect reflection of the population Sampling randomly is easier than sampling nonrandomly Actually, there is no statistically valid reason for sampling randomly

Sampling randomly tends to reduce sampling bias or risk

Match the following: Step One (Daniel) Step Five (Truth) Step Three (Discern) Step Two (Can) Step Four (More) 1. Collect Data 2. Take Action 3. Design the Study 4. Describe the Data 5. Make Inferences

Step One (Daniel) - 3. Design the Study Step Five (Truth) - 2. Take Action Step Three (Discern) - 4. Describe the Data Step Two (Can) - 1. Collect Data Step Four (More) - 5. Make Inferences

A study conducted by researchers from the Department of Education wanted to know the average debt of college students in the United States. In order to obtain a sample representative of all students, the researchers divided college students into the four classes (freshman, sophomore, junior, and senior) and then took a random sample of students from each class. Which sampling method did they use? Stratified random sampling Systematic random sampling Cluster sampling Simple random sampling

Stratified random sampling

Students in an Introductory Statistics class at BYU-Idaho were studying prices of cold cereal at grocery stores in Rexburg. To get a sample of cold cereal prices, they went to Albertson's and rolled a die to decide which box from the left of the top shelf they would start on. They then recorded every 6th cereal after the first, moving from left to right down the shelves, recording the name, size, and price of each cereal in their sample. Which sampling method did they use? Stratified random sampling Systematic random sampling Cluster sampling Simple random sampling

Systematic random sampling

Mumbai, India is a quickly growing city of importance in its own country as well as the global economy. A marketing research firm has been asked by a prominent fast food restaurant to help determine if the citizens of Mumbai would support this fast food business. From a list of all registered tax payers, 3000 names are randomly selected. Each individual on the list is mailed a brief questionnaire. The researchers receive 1049 responses. The sample is: The 1049 people who respond. The citizens of Mumbai. Cannot be determined.

The 1049 people who respond.

You want to become the next Jonas Salk and produce a vaccine that will help cure children of Respiratory Syncytial Virus (RSV). You test the vaccine and compare it to a placebo and randomly choose one group of children to take the vaccine and one group to take the placebo. What (or who) are the experimental units or subjects? The children The parents The administrators The vaccine and placebo

The children

Mumbai, India is a quickly growing city of importance in its own country as well as the global economy. A marketing research firm has been asked by a prominent fast food restaurant to help determine if the citizens of Mumbai would support this fast food business. From a list of all registered tax payers, 3000 names are randomly selected. Each individual on the list is mailed a brief questionnaire. The researchers receive 1049 responses. The population is: The 1049 people who respond. The citizens of Mumbai. Cannot be determined

The citizens of Mumbai.

Say that you are a researcher for a large pharmaceutical company that has produced a new drug that is believed to help reduce the risk of developing arthritis. You test the drug and compare it to a placebo by randomly choosing one group of men and women in their 50's to take the drug and one group of men and women in their 50's to take a placebo. Each participant takes the drug or placebo for a period of 10 years, after which the effects of the drug are measured against the effects of the placebo. What are the treatments? All men and women in their 50's The men and women who took the drug or placebo The researchers Only the men and women who took the drug The drug and placebo

The drug and placebo

 The teacher recorded the mean and median of the hourly wage for each student. Unfortunately, he forgot to label them. The numbers he wrote down were: $11.25/hour and $9.38/hour. Which would be the mean and which would be the median? The mean is $9.38/hour. The median is $11.25/hour. The mean is $11.25/hour. The median is $9.38/hour. This cannot be determined from the information given

The mean is $11.25/hour. The median is $9.38/hour.

For a Math 221 project, one group of students studied the ages of students on the BYU-Idaho campus. They collected data from a random sample of n = 100 students. The sample mean was 21.2 and the sample standard deviation was 2.61. An excerpt of their data is given below. ID GENDER AGE 1 Female 21 2 Male 18 3 Male 12 4 Female 20 : : : 99 Male 25 The group notices an error in their data. The age of one of the males (ID=3) was entered incorrectly. He is actually 21 years old. When the error is corrected, what will happen to the sample mean? The mean will increase. The mean will decrease. The mean will stay the same. It is not possible to determine this without the full data set.

The mean will increase.

Say that you are a researcher for a large pharmaceutical company that has produced a new drug that is believed to help reduce the risk of developing arthritis. You test the drug and compare it to a placebo by randomly choosing one group of men and women in their 50's to take the drug and one group of men and women in their 50's to take a placebo. Each participant takes the drug or placebo for a period of 10 years, after which the effects of the drug are measured against the effects of the placebo. What (or who) are the experimental units or subject? All men and women in their 50's The men and women who took the drug or placebo The researchers The drug and placebo

The men and women who took the drug or placebo

Which of the following variables is/are quantitative? (Mark all that apply) The number of people in a randomly selected classroom on campus The 3 most common brands of car found in the US The telephone number of a randomly selected business in town

The number of people in a randomly selected classroom on campus

You want to become the next Jonas Salk and produce a vaccine that will help cure children of Respiratory Syncytial Virus (RSV). You test the vaccine and compare it to a placebo and randomly choose one group of children to take the vaccine and one group to take the placebo. What are the treatments? The number of incidences of the virus The children The administrators The vaccine and placebo

The vaccine and placebo

What is the standard deviation of the data recorded in the boxplot? 2 4 10 This cannot be determined from the boxplot

This cannot be determined from the boxplot

Redbox is an increasingly popular way to rent movies in the US. Individuals can go to a Redbox kiosk and have a wide variety of movies to choose from. A study was done in which researchers observed the duration of time (in seconds) individuals spent making a decision on which movie to rent at a Redbox. 800 700 - 600 I 500 I 400 I 300 I 200 I 100 [-----] 0 I - Based on the box-plot, what is the value of the mean? 105 seconds 62 seconds 187 seconds This cannot be determined.

This cannot be determined.

Suppose you take the Medical College Admission Test (MCAT) and your score is the 32nd percentile. How do you interpret this result? You scored 32 points higher than the average person who took the exam. 32% of the people who took the exam scored higher than you did. You answered only 32% of the questions correctly. You scored as high as or higher than 32% of the people who took the exam.

You scored as high as or higher than 32% of the people who took the exam.

Approximately what percentage of the data lie between 4 and 8 hours? about 25% about 33% about 50% about 75% This cannot be determined from the boxplot.

about 50%

In a study to determine the average wage of working people in Mumbai, which of the following would be the best sample? every tenth worker that you meet as you travel the streets of Mumbai all of the workers in one working district of Mumbai many randomly selected workers in each of several working districts of Mumbai all the female workers

many randomly selected workers in each of several working districts of Mumbai

Which of the following sets of numbers has the largest standard deviation? (No calculations are required.) {4,5,6,7} {12,13,14,15} {18,18,18,18} {1,2,9,10}

{1,2,9,10}