
Concept explainers
Population vs. Sample (Example 1) In 2017 the Gallup poll surveyed 1021 adults in the United States and found that
a. Identify the population and the sample.
b. What is the parameter of interest? What is the statistic?
a.

Determine the population and the sample.
Answer to Problem 1SE
Population comprises all adults in the U.S., whereas the sample is the 1021 adults surveyed.
Explanation of Solution
The Gallup poll surveyed 1021 adults of the United States in 2017 and found that 57% of them were in favor of a ban on smoking in public places.
A population is a group of objects or people that the researcher wants to study. In the given case, the researcher wants to study the adults’ reaction in the U.S towards the ban on smoking in public places. Hence, the population of the study is ‘all the adults living in the United States’.
A sample is a collection of people or objects taken from the population of interest. As the population of the U.S. is too vast to study, a sample of 1021 adults are surveyed. Hence, the sample of the study is ‘1021 adults surveyed in the U.S’.
b .

Determine the parameter of interest and statistic.
Answer to Problem 1SE
The parameter of interest is the percentage of all U.S. adults who are supporting the ban on smoking in public places, whereas the statistic is the 57% of adults in the sample who are in favor of the ban.
Explanation of Solution
Parameter of interest is a numerical value that characterizes some aspect of the population. Here, the researcher wishes to know the proportion of adults in favor of the ban on smoking in public places in the United States. Thus, the parameter of interest is the proportion of all adults in the U.S. who are in favor of the ban on smoking in public places.
Statistic is a numerical characteristic of a sample of data, which is used to estimate the parameters. In this case, the percentage of adults in the sample who are supporting the ban of smoking in public places, that is 57%, is the statistic.
Want to see more full solutions like this?
Chapter 7 Solutions
EP INTRODUCTORY STATISTICS-MYSTATLAB
Additional Math Textbook Solutions
Precalculus
Elementary Statistics: Picturing the World (7th Edition)
Pre-Algebra Student Edition
A First Course in Probability (10th Edition)
Elementary Statistics (13th Edition)
- Question: A company launches two different marketing campaigns to promote the same product in two different regions. After one month, the company collects the sales data (in units sold) from both regions to compare the effectiveness of the campaigns. The company wants to determine whether there is a significant difference in the mean sales between the two regions. Perform a two sample T-test You can provide your answer by inserting a text box and the answer must include: Null hypothesis, Alternative hypothesis, Show answer (output table/summary table), and Conclusion based on the P value. (2 points = 0.5 x 4 Answers) Each of these is worth 0.5 points. However, showing the calculation is must. If calculation is missing, the whole answer won't get any credit.arrow_forwardBinomial Prob. Question: A new teaching method claims to improve student engagement. A survey reveals that 60% of students find this method engaging. If 15 students are randomly selected, what is the probability that: a) Exactly 9 students find the method engaging?b) At least 7 students find the method engaging? (2 points = 1 x 2 answers) Provide answers in the yellow cellsarrow_forwardIn a survey of 2273 adults, 739 say they believe in UFOS. Construct a 95% confidence interval for the population proportion of adults who believe in UFOs. A 95% confidence interval for the population proportion is ( ☐, ☐ ). (Round to three decimal places as needed.)arrow_forward
- Find the minimum sample size n needed to estimate μ for the given values of c, σ, and E. C=0.98, σ 6.7, and E = 2 Assume that a preliminary sample has at least 30 members. n = (Round up to the nearest whole number.)arrow_forwardIn a survey of 2193 adults in a recent year, 1233 say they have made a New Year's resolution. Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. The 90% confidence interval for the population proportion p is (Round to three decimal places as needed.) J.D) .arrow_forwardLet p be the population proportion for the following condition. Find the point estimates for p and q. In a survey of 1143 adults from country A, 317 said that they were not confident that the food they eat in country A is safe. The point estimate for p, p, is (Round to three decimal places as needed.) ...arrow_forward
- (c) Because logistic regression predicts probabilities of outcomes, observations used to build a logistic regression model need not be independent. A. false: all observations must be independent B. true C. false: only observations with the same outcome need to be independent I ANSWERED: A. false: all observations must be independent. (This was marked wrong but I have no idea why. Isn't this a basic assumption of logistic regression)arrow_forwardBusiness discussarrow_forwardSpam filters are built on principles similar to those used in logistic regression. We fit a probability that each message is spam or not spam. We have several variables for each email. Here are a few: to_multiple=1 if there are multiple recipients, winner=1 if the word 'winner' appears in the subject line, format=1 if the email is poorly formatted, re_subj=1 if "re" appears in the subject line. A logistic model was fit to a dataset with the following output: Estimate SE Z Pr(>|Z|) (Intercept) -0.8161 0.086 -9.4895 0 to_multiple -2.5651 0.3052 -8.4047 0 winner 1.5801 0.3156 5.0067 0 format -0.1528 0.1136 -1.3451 0.1786 re_subj -2.8401 0.363 -7.824 0 (a) Write down the model using the coefficients from the model fit.log_odds(spam) = -0.8161 + -2.5651 + to_multiple + 1.5801 winner + -0.1528 format + -2.8401 re_subj(b) Suppose we have an observation where to_multiple=0, winner=1, format=0, and re_subj=0. What is the predicted probability that this message is spam?…arrow_forward
- Consider an event X comprised of three outcomes whose probabilities are 9/18, 1/18,and 6/18. Compute the probability of the complement of the event. Question content area bottom Part 1 A.1/2 B.2/18 C.16/18 D.16/3arrow_forwardJohn and Mike were offered mints. What is the probability that at least John or Mike would respond favorably? (Hint: Use the classical definition.) Question content area bottom Part 1 A.1/2 B.3/4 C.1/8 D.3/8arrow_forwardThe details of the clock sales at a supermarket for the past 6 weeks are shown in the table below. The time series appears to be relatively stable, without trend, seasonal, or cyclical effects. The simple moving average value of k is set at 2. What is the simple moving average root mean square error? Round to two decimal places. Week Units sold 1 88 2 44 3 54 4 65 5 72 6 85 Question content area bottom Part 1 A. 207.13 B. 20.12 C. 14.39 D. 0.21arrow_forward
- Holt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGALGlencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
- Big Ideas Math A Bridge To Success Algebra 1: Stu...AlgebraISBN:9781680331141Author:HOUGHTON MIFFLIN HARCOURTPublisher:Houghton Mifflin Harcourt




