A research wants to determine if pre-natal exposure to the hormones in birth control pills alters the sex makeup of midshipman fish populations (which are typically half male and half female). Specifically, the researcher wishes to test the hypothesis that exposure to hormones will increase the number of females in the population. The researcher exposes a group of pregnant midshipman fish to birth control hormones and records the sex of the first 14 offspring birthed. They then observe that 4 are female. Use a sign test and a alpha of .05 to test the indicated hypothesis. What is the critical value?

You are a researcher who wants to study how people’s feelings towards Congress change over time. You send a survey to the same 1,000 people at two time points: 2005 and 2015. What type of study is this? A. Open-ended response study B. Focus group study C. Two-wave panel study D. Three-wave panel study

The following is based on information from The Wolf in the Southwest: The Making of an Endangered Species, by David E. Brown (University of Arizona Press). Before 1918, the proportion of female wolves in the general population of all southwestern wolves was about 50%. However, after 1918, southwestern cattle ranchers began a widespread effort to destroy wolves. In a recent sample of 37 wolves, there were only 11 females. One theory is that male wolves tend to return sooner than females to their old territories, where their predecessors were exterminated. Do these data indicate that the population proportion of female wolves is now less than 50% in the region? Use α = 0.01. (a) What is the level of significance? State the null and alternate hypotheses. O Ho: P 0.5 O Ho: P = 0.5; H₁: p 5 and nq > 5. O The Student's t, since np > 5 and ng > 5. The standard normal, since np < 5 and nq < 5. O The Student's t, since np < 5 and nq < 5. What is the value of the sample test statistic? (Round…

A. Headache Pain : There are many over-the-counter pain relievers. By the end of the semester, you have a tremendous headache and are looking for the most effective pain relief available. You conduct a study comparing the three most popular pain relievers and a placebo to see which work best. You use only subjects with headaches and record the amount of time (in minutes) it takes for their headache to go away after they receive the medication. You randomly assign 60 participants to one of the four conditions using a double- + blind procedure. (Use a = Placebo 70 Drug A 30 Drug B 10 Drug C 10 30 60 40 20 50 40 10 10 60 30 40 10 10 40 30 30 30 30 30 10 40 20 20 20 60 40 20 30 50 30 30 10 30 30 20 20 60 20 10 10 20 40 20 30 20 50 20 10 40 20 30 30 State the hypotheses Critical value and df Test statistic

A state fisheries commission wants to estimate the number of bass caught in a given lake during a season in order to restock the lake with the appropriate number of young fish. The commission could get a fairly accurate assessment of the seasonal catch by extensive “netting sweeps" of the lake before and after a season, but this technique is much too expensive to be done routinely. Therefore, the commission samples a number of lakes and record the seasonal catch (thousands of bass per square mile of lake area) and size of lake (square miles). A simple linear regression was performed and the following R output obtained. Estimate Std. Error t value Pr(>|t|) (Intercept) 2.5463 0.4427 5.7513 0.0000 size 0.0667 0.3672 0.1818 0.8578 If a scatterplot showed a non-linear relationship between the response and explanatory variables, what should be done? O Nothing. Continue the analysis as is. Stop the analysis. Perform a natural log transformation on the response variable first. O Perform a…

Consider the following studies. Study I: A researcher randomly divided 200 high school students into two groups. The first group was told to not exercise. The second group was told to exercise at least 5 hours each week. At the end of two months, the heart rates of each participant in each group were measured at rest. It was found that the group that exercised 5 hours a week had a significantly lower average heart rate. Study II: A researcher gathered 200 high school students randomly, asked them how long they exercised each week, and then measured their heart rates at rest. It was found that students who exercised at least 5 hours a week had a significantly lower average heart rate. Part A: Which study was experimental? Why?  Study IStudy II Part B: List the explanatory and response variables in the studies.  Explanatory: heart rate; Response: exercise timeExplanatory: student; Response: amount of exerciseExplanatory: exercise time; Response: heart rate Part C: State whether the…

The Stanford University Heart Transplant Study was conducted to determine whether an experimental heart transplant program increased lifespan. Each patient entering the program was officially designated a heart transplant candidate, meaning that he was gravely ill and might benefit from a new heart. Patients were randomly assigned into a treatment and control groups. Patients in the treatment group received a transplant and those in the control group did not. The table below displays how many patients survived and died in each group.     control treatment alive 4 24 dead 30 45 Explain why we cannot construct a confidence interval or a hypothesis test (hint: consider the conditions).

The statistics department at a large Midwestern university is interested in how students feel about their introductory statistics course. They decide to randomly select 60 introductory stats students to give a survey, 10 from both the freshman and sophomore class ranks and 20 from both the junior and senior class ranks. They discover that of the 60 total respondents, 73% have a positive attitude toward intro stats. The proportion of the 60 introductory statistics students surveyed by the statistics department that did have positive attitudes toward intro stats (73%) is called a O a. population parameter O b. residual O c. correlation coefficient O d. sample statistic 3 Stat100 Practice..pdf 7 Writing Prompt 3.docx E Online Syllabus J...pdf E Bios357Schedul.pdf SH OCT1 étv 20 F3 トI A FI F9 F10 F5 F7 F8 F2 F4 %23 2$ & * 2 4. 5 6 7 8 9 Q W E T Y S F G H K しの

he federal government is interested in determining whether salary discrimination exists between men and women in the private sector. Suppose a sample of 16 women and 25 men are taken from the population of first-level managers in the private sector. The information is summarized as follows (amounts are in thousands of dollars):     Women Men   n   16   25 X¯ $26.4 $33.3 S $2.6 $3.2   Test H0 : µ1 = µ2  against H1 : µ1 = µ2  where µ1  and µ2  are the mean salary of first level female  and male managers, respectively. Use α = 0.05 and assume equal variances.       Test statistic = −2.68 and reject H0       Test statistic = −7.22 and reject H0       Test statistic = −2.68 and fail to reject H0     Test statistic = −7.22 and fail to reject H0

A pharmaceutical company is testing the effectiveness of its vaccine across two different age brackets. They take a sample and split the participants up into two separate groups. Group A consists of 44 people who are between ages 13 and 18. Group B consists of 58 people between ages 19 and 26. After being administered the vaccine, it was found that 37 people from group A were immune to the virus and 42 people from group B were immune. What proportion of people from Group A were immune? What proportion of people from Group B were immune? What proportion of people in this study were immune?