An experiment was conducted to investigate whether submersion in cold water causes a lower heart rate. The experiment used 50 volunteers. The 25 youngest volunteers had their heart rate measured while holding their breath for 30 seconds with their face submerged in cold water. The 25 oldest volunteers had their heart rate measured while holding their breath for 30 seconds with their face not submerged in cold water. The mean heart rate for volunteers who had their face submerged in cold water was lower than the mean heart rate for volunteers who did not have their face submerged in cold water. Which of the following elements of a well-designed experiment is missing? I. Comparison of at least two treatment groups II. Random assignment of treatments to experimental units III. Replication (A) I only (B) II only (C) I and II only (D) II and III only (E) I, II, and III

The Graduate Record Exam is a standardized test taken by many graduating college seniors. GRE scores are often included in applications to masters or doctoral programs. Suppose that a psychology major received a score of X = 160 on the verbal section of the GRE and a score of X = 159 on the quantitative section of the GRE. The mean verbal GRE score for the years 2014-2017 among psychology majors was M = 152, s = 7. The mean quantitative score for the same years was M = 149, s = 7. Use z-scores to describe the student's performance relative to other psychology majors. On which section, verbal or quantitative, was the student's performance better? Round your answers to two decimal places. Verbal z-score is z = Quantitative z-score is z = The student's performance relative to other psychology majors was weaker stronger on the quantitative GRE than on the verbal GRE.

A psychology student conducted a study on using a chief executive​ officer's facial structure to predict a​ firm's financial performance. The facial​ width-to-height ratio​ (WHR) for each in a sample of 47 CEOs at publicly traded firms was determined. The sample resulted in x=2.23 and s=0.35. The student wants to predict the financial performance of a firm based on the value of the true mean facial WHR of CEOs. The student wants to use the value of μ=2.1. Do you recommend he use this​ value? Conduct a test of hypothesis for μ to help you answer the question. Specify all the elements of the​ test, including H0​, Ha​, test​ statistic, p-value, and your conclusion. Test at α=0.01.

Hellen has just started a new years competition for her local climbing gym. There are two categories for this competition: singles and group (18 people). The rules are simple, put in the most hours in one months time and you get a guided tour to climb Ten Sleep canyon. She knows from running this competition over the years that the number of hours climbers at her gym spend training during this competiton is approximately normal and their mean competition hours per month in the gym are 24 hrs with a standard devaition of 6 hrs. Singles Distribution: X~N( , ) Group Distribution: x̄~N( , ) The winning single participant last year was in the 97 th percentile.... how many hours did the winner accumulate over the month?   One of Hellan's friends Dave put in 27.12 hours on the wall. What is the probablity that another individual will beat his time?   If someone puts in between 25.5-32.1 hours on the wall they get a Mountain Goat shirt. What percent of the singles competitors is expected to…