A researcher wants to determine if taking a certain drug monthly will reduce the chances of developing dementia in women. A group of 500 women between the ages of 55 and 65 were utilized in the study. Each woman was randomly placed into one of two groups. One group received the drug and the other group received a placebo. The drug/placebo was administered to each woman each month for 10 years. At the end of the study the proportion of woman who developed dementia were determined for both groups. Match the letters to the appropriate question by writing the letter in the blank 2 1. dementia Who or what is the sample in this study? Who or what is an individual in this study? 2. the 500 women 3. the placebo
Added by Michael H.
Close
Step 1
Step 1: The sample in this study is the 500 women between the ages of 55 and 65 who were utilized in the study. Show more…
Show all steps
Your feedback will help us improve your experience
Marc Lauzon and 96 other Intro Stats / AP Statistics educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
Use the technology of your choice to conduct the required analyses. An issue of Science News (Vol. $163,$ No. $22,$ pp. $341-342$ ) reported that the Women's Health Initiative cast doubts on the benefit of hormonereplacement therapy. Researchers randomly divided 4532 healthy women over the age of 65 years into two groups. One group, consisting of 2229 women, received hormone-replacement therapy; the other group, consisting of 2303 women, received placebo. Over 5 years, 40 of the women receiving the hormonereplacement therapy were diagnosed with dementia, compared with 21 of those getting placebo. a. At the $5 \%$ significance level, do the data provide sufficient evidence to conclude that healthy women over 65 years old who take hormone-replacement therapy are at greater risk for dementia than those who do not? b. Determine and interpret a $95 \%$ confidence interval for the difference in dementia risk rates for healthy women over 65 years old who take hormone-replacement therapy and those who do not.
Inferences for Population Proportions
Inferences for Two Population Proportions
2. Identifying populations, samples, statistics, parameters, and variables A psychology professor wants to know whether study skills are related to memory quality in current first-year students at her small college. Participants in the study (first-year students at her college) complete an online memory task. The students are first shown a list of 60 words. Next they are shown a list that includes five new words that are conceptually similar to words on the original list. Then they are asked to identify the words on the second list that appeared on the original list. She uses the percentage of new but conceptually similar words that were mistakenly thought to be on the original list as her measure of memory quality. She also asks the students to report several characteristics such as their age, their gender, and a self-assessment of their study skills. Each of the 750 first-year students (338 males and 412 females) at her school volunteers to participate. The professor chose 75 students at random to complete the memory task and answer the questions. The average percentage of new but conceptually similar words that were mistakenly thought to be on the original list was 34%. The professor infers that if all 750 first-year students had completed the study, the results would show that an average of 34% (plus or minus sampling error) of new words were mistakenly identified as original words because they were conceptually similar. Which of the following are variables in the study? Check all that apply. [ ] The 75 students [X] The students' self-assessments of their study skills [ ] The students' percentage of new but conceptually similar words that were mistakenly thought to be on the original list [ ] The 750 students What is the population in the study? ( ) The 75 students who participated in the study ( ) The 750 first-year students at the college (X) The 34% of new words mistakenly identified as original words because they were conceptually similar What is the sample in the study? ( ) The 75 students who participated in the study ( ) The 34% of new words mistakenly identified as original words because they were conceptually similar
Madhur L.
6. Identifying the components of a study A psychology professor wants to know whether confidence in memory skills is related to memory quality in current first-year students at her small college. Participants in the study (first-year students at her college) complete an online memory task. The students are first shown a list of 60 words. Next they are shown a list that includes 10 words that were on the original list. Then they are asked to identify the words on the second list that appeared on the original list. She uses the percentage of words that were correctly recognized on the original list as her measure of memory quality. She also asks the students to report several characteristics such as their age, their gender, and a self-assessment of their memory skills. Each of the 1,000 first-year students (543 males and 457 females) at her school volunteers to participate. The professor chose 100 students at random to complete the memory task and answer the questions. The average percentage of words that were correctly recognized on the original list was 68%. The professor infers that if all 1,000 first-year students had completed the study, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list. Which of the following are variables in the study? Check all that apply. The 1,000 students The 100 students The students’ self-assessment of their memory skills The students’ percentage of words that were correctly recognized on the original list What is an example of a statistic in the study? 68%, the average percentage of the original list expected to be correctly recognized by the 1,000 students 68%, the average percentage of words that were correctly recognized as being from the original list by the 100 students 457 females and 543 males What is an example of a parameter in the study? 100 students 68% of words that were correctly recognized on the original list by the 100 first-year students The actual average percentage of words that would be correctly recognized as being from the original list by the 1,000 first-year students What is an example of the professor using descriptive statistics? She infers that if all 1,000 students had done the experiment, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list. She randomly chooses the 100 students to represent the 1,000 volunteers. She reports that the average percentage of words that were correctly recognized on the original list was 68%. What is an example of the professor using inferential statistics? She reports that the average percentage of words that were correctly recognized on the original list was 68%. She characterizes the first-year students at the college as consisting of 543 males and 457 females. She infers that if all 1,000 students had done the experiment, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list. The psychology professor's study is _______________.
Mahajan A.
Recommended Textbooks
Elementary Statistics a Step by Step Approach
The Practice of Statistics for AP
Introductory Statistics
Transcript
Watch the video solution with this free unlock.
EMAIL
PASSWORD