Statistics and Probability questions and answers in April 2021

Based on past data, the owner of a store believes that 83% of customers who walk in his store will make a purchase. Say, a random sample of 63 customers walks in his store and 68% of these made a pur...
What are the tensions between the pressure to manipulate data to support an existing desired outcome and employing proper statistical techniques to determine an outcome that is in line with ethical st...
19 A. A  repeated-measures  analysis of variance produces SS withingp  = 50 and SS betweenpers  = 30  For this analysis, what is the value of SS error ? a.20 b.It cannot be determined from the in...
The accompanying data represent the percentages of teenagers in various countries that have used certain drugs. Complete parts (a) through (c) below. Country A B C D E F G H J K Drug 1, x 21 18 40 5 ...
Two different simple random samples are drawn from two different populations. The first sample consists of 30 people with 16 having a common attribute. The second example consists of 1900 people with ...
According to the data that the real-estate investors collected, the mean individual apartment price within a 41-kilometer (about 25 miles) radius of the Central Business District of Melbourne is $45...
To determine whether training in a series of workshops on creative thinking increases IQ scores, a total of 70 students are randomly divided into treatment and control groups of 35 each. After two mon...
A) True or False: The linear model used in Multiple Regression appears as the exponent in the predicted probability equation of Logistic Regression.  B) If your outcome is continuous can you use logi...
Scenario: A Data 275 teacher just gave a quiz to the 10 students in the class. The data is below. Please use SPSS, Excel, Minitab, or other familiar device to answer the questions that follow. Test Sc...
Scenario: Below are the results of an independent samples t-test used to determine if two test forms were of the same difficulty (as measured by mean scores of a matched sample on each form). The test...
Under the assumptions of a paired samples t-test, what is assumed to be normally distributed in the population? a. The mean b. The outcome measure c. The standard deviations d. The differences between...
If I was interested in graphically examining the normality of my test scores, which method/graph would be most appropriate and informative? a. Pie chart b. Bar chart c. Box plot (Box and Whiskers Plot...
If I owned a car dealership and wanted a quick graphical way to determine which of my salespersons sold the most units in a given quarter, which method would be most appropriate and informative? a. Pi...
For questions 15-17, refer to the following information:  Thyroid-stimulating hormone (TSH) is a hormone produced by the pituitary gland in your brain. This gland tells the thyroid to produce thyroxi...
For questions 9-13,  the duration of time from first exposure to HIV infection to AIDS diagnosis is called the incubation period. The incubation period of a random sample of 9 people living with HIV ...
For questions 1-3, refer to the following information:  As the current opioid epidemic highlights the increasing injection drug use in rural communities, the relationship of injection drug use and it...
9) The tutoring supervisor at the tutoring center at the large community college (from problem 7 and 8) calculates the average grade for 105 students that regularly attend statistics tutoring and calc...
8) The tutoring supervisor at the tutoring center at the large community college (from problem 7) collects the data for 105 students that regularly attend statistics tutoring and records their grades....
8. I conduct a factorial study with gender (male or female), age (young or old) and their interaction as predictors of depressive symptoms. I find that age is significantly predictive of depressive ...
7) The tutoring center at a large community college states that the average grade of a student that regularly attends statistics tutoring is at least an 85. Note problems 8 and 9 refer to this problem...
6) The engineer that works at Ford Motors for problems (4) and (5) calculates the "test statistic" (Z or T test test , ) and calculates a value of −1.51 A) If the significance level is  =.05 Stat...
5) The engineer that works at Ford Motors for problem (4) collects data for 26 Ford Mustangs and records how it takes them to go 0 to 60 miles an hour. A) What table should you use to obtain the criti...
3) The biologist specializing in wildlife in the northern region for Problems (1) and (2) calculates the "test statistic" (Z or T test test , ) and calculates a value of 2.00 A) If the significance le...
Consider the following summary from from a simple linear regression involving a very small data set of n = 5 observations. Coefficients:            Estimate    Std. Error     Interc...
Suppose researchers draw a sample of 250 individuals from a population, and carry out a t test of the null hypothesis that the true mean is 300, against the alternative hypothesis that it is less than...
Previous Page Next Page Page 21 of 25 Question 21 (1 point) Suppose that in a certain very large corporation, the proportion of salaried employees that have a university degree is 0.87. Suppose that ...
Suppose we are about to carry out 95 independent hypothesis tests. We intend to carry out each test at a significance level of 0.05. Suppose that the assumptions of each test are true, and, unknown to...
Question 11 (1 point) Suppose researchers draw a sample of 650 breakfast sandwiches from a certain fast- food restaurant, and carry out a t test of the null hypothesis that the true mean sodium conte...
The following output summarizes the results of a simple linear regression of a response variable Y on an explanatory variable X. Coefficients:          Estimate Std. Error  t value  Pr(&...
The drop down choices for population parameter include: the numbers of customers in the sample that prefer a window seat, the number of customers sampled, the proportion of all customers in the sample...
Let  x  be a random variable representing dividend yield of bank stocks. We may assume that  x  has a normal distribution with 𝜎 = 2.5%. A random sample of 10 bank stocks gave the followi...
A researcher performs three independent hypothesis tests each at the 5% significance level. Determine the probability of observing exactly 1 Type I Error. (Round your final answer to the nearest hund...
12. According to a report published by the Pew Research Center in February 2010, 61% of millennials ( Americans in their teens and 20s) think that their generation has a unique and distinctive identit...
Suppose the mean height in inches of all 9th grade students at one high school is estimated. The population standard deviation is 6 inches. The heights of 10 randomly selected students are 61, 72, 61,...
Y = Blood Glucose Level (mg/dL) X = Number of servings of candy eaten each week. You obtain the following regression equation from your analysis: yhat = 100 - 0.87*x where the value of -0.87 has a p-v...
Y = Yearly Income (measured in thousands of dollars) X = 1 if someone has a bachelor's degree or higher and 0 otherwise You obtain the following regression equation from your analysis: yhat = 33 + 16...
Y = Blood Glucose Level (mg/dL) X = Number of servings of candy eaten each week. You obtain the following regression equation from your analysis: yhat = 80 + 0.57*x where the value of 0.57 has a p-va...
Y = Yearly Income (measured in thousands of dollars) X = 1 if someone has a bachelor's degree or higher and 0 otherwise You obtain the following regression equation from your analysis: yhat = 46.9 - ...
Y = Blood Glucose Level (mg/dL) X = Number of servings of candy eaten each week. You obtain the following regression equation from your analysis: yhat = 100 - 0.87*x where the value of -0.87 has a p-...
The relationship between IgM confirmed-rubella infection (i.e., using a blood antibody test for rubella given if requested by the attending physician) during pregnancy and the development of congenit...
In an outbreak of varicella (chickenpox) in Oregon in 2002, varicella was diagnosed in 18 of 152 vaccinated children compared with 3 of 7 unvaccinated children. a. Calculate the risk ratio (relative ...
3 In a cohort study of 10,000 persons, free of lung cancer that started 10 years ago, 18% were current smokers at the time of enrollment. Since enrollment, 30 persons developed lung cancer When revie...
The standard deviation of the population of iQ scores is standardized to be 16 points calculate the standard error of the mean for (round to the nearest hundredth) 1) sample size of 12 2) a sample siz...
Kings Hospital must determine the mean number of days patients stay at the hospital. The data below is generated for the entire number of 20 patients. The 6 underlined numbers are randomly drawn samp...
Kings Hospital must determine the mean number of days patients stay at the hospital. The data below is generated for the entire number of 20 patients. The 6 underlined numbers are randomly drawn samp...
5) Based on a normal distribution which score is better ? A score 76 on a test for which the mean was 80 and the standard deviation was 5 or a score of 82 on a test for which the mean was 86 and the s...
Assume that the mean starting salary for last years accounting was 55,000 with a standard deviation of 5,000. If their salaries were normally distributed find 1) the zscore for a salary of $49,000 2) ...
Sociologists say that 83% of married women claim that their husband's mother is the biggest bone of contention in their marriages. Suppose that 6 married women are having coffee together one morning.?...
A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. A group of 50 men and 40 women were asked if thought sexual discrimination was a problem in th...
A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. A group of 50 men and 40 women were asked if thought sexual discrimination was a problem in th...
A powerful women's group has claimed that men and women differ in attitudes about sexual discrimination. A group of 50 men and 40 women were asked if thought sexual discrimination was a problem in th...
The t test for the difference between the means of 2 independent populations when standard deviations are unknown assumes that the A. samples are randomly and independently drawn B. population varianc...
A real estate company is interested in testing whether the mean time that families in Gotham have been living in their current home is less than families in Metropolis . Assume that the two population...
The following contains the results of a test to determine whether the proportion of satisfied customers at 2 resorts are the same or different Group 1Number of Items of Interest160Sample Size200Group ...
A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries. Of primary interest to the researcher was the effect of gender on starting salaries...
A researcher numbers each household in the city and uses a random number generator to select individual households for the sample. By chance, none of the households chosen were households of single mi...
Chapter 13, numbers 13.8 and 13.10     13.8 Assume that, on average, healthy young adults dream 90 minutes each night, as inferred from a number of measures, including rapid eye movement (REM) sleep...
1. One of the most common types of information retrieval processes is document database searching. An experiment was conducted to investigate the variables that influence search performance in the Med...
Answer choices: simulation, experiment, survey/poll, observational study Read each scenario and identify the method used for collecting data. 1. The department of public safety wants to reduce the amo...
Answer choices: Untrue Response, Leading Questions, Interviewer Influence, Faulty Recall, Voluntary Response, Non-Response, Undercoverage Check for Understanding Instructions: For the following survey...
Answer choices for number 2 : Faulty recall, Leading questions, Interviewer influence, Non-response, Undercoverage, Untrue responses, Vague wording, Voluntary response Please read the following articl...
Suppose that IQs of adult Canadians follow a normal distribution with standard deviation 15. A random sample of 30 adult Canadians has mean IQ of 112. We would like to construct a 92% confidence inter...
Suppose that 40% of students at a university drive to campus. 1.If we randomly select 200 students from this university, what is the approximate probability that less than 35% of them drive to campus?...
Weights of suitcases checked in at the airport follow a normal distribution with mean 28 pounds and standard deviation 5 pounds. What is the probability that the total weight of a random sample of ten...
1 Some variables of interest has a a left skewed distribution with a mean of 100 and a standard deviation of 10. we take a random sample of size 5. can we calculate the probability that the sample mea...
1 suppose the IQ's of adult Canadians follow a normal distribution with standard deviation 15. A random sample os 30 adult Canadians has a mean IQ of 112. We would like to construct a 97% confidence i...
1 Some variables of interest has a a left skewed distribution with a mean of 100 and a standard deviation of 10. we take a random sample of size 5. can we calculate the probability that the sample mea...
13.8 Assume that, on average, healthy young adults dream 90 minutes each night, as inferred from a number of measures, including rapid eye movement (REM) sleep. An investigator wishes to determine whe...
1.A researcher is doing a study examining the influence of exercise on blood pressure. there are 4 groups, each with 7 people: Yoga, Weight training, Walking, Aerobics. SSbg is 30 and SSwg is 70. Wh...
For a randomized clinical trial (just like for many other types of epidemiologic studies), the extent to which the patients included in the study are representative of all patients with the disease u...
An experimental study is conducted to compare the effect of two treatments. The power of the study is 85%. Which of the following statements is true? (choose one best answer) O The probability of mak...
In a study comparing a new therapy with an existing (standard) therapy, the use of.. (choose one best answer) O historical controls ensure unpredictability of assignment (selection) to the new and ex...