(a) Identify the elements of the population and give the population size. (b) Identify the elements of the sample and give the sample size. (c) Suppose that the sociologist were interested in the proportion with less than four children. (i) 'What is the value of the statistic? (ii) What is the value of the parameter?

REVIEWING PSYCHOLOGICAL STATISTICS CONCEPTS Note: All participants are randomly assigned to the groups PROBLEM 3: The researcher conducted an experiment to determine whether temperature affects the test performance of college students.  He matched the participants according to the GPA prior random assignment to the experimental and control group.  One group took a 50-item test in a warm room while the other group took the same test in a cold room.  He wanted to test the hypothesis at 0.05 level of significance.  The following results were gathered:

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Each of the boxplots shown summarizes 24 student scores on a recent test in two different classes. The boxplots are drawn using a common numerical scale. Which of the following must be true?    1. The lower 25% of Class B are much more spread out than the lower 25% of Class A 2. More people scored below the lower quartile for Class A than Class B 3. The distribution for Class B is skewed left and has a noticeable outlier as well, while the distribution for Class A is somewhat skewed right 4.Class A had more people between the median and the lower quartile than Class B. 3.The distribution for Class A is somewhat symmetric, while the distribution for Class B is skewed right with a noticeable outlier as well

In each situation, find the value of the standardized statistic for the sample mean, and indicate whether the standardized statistic is a t-statistic or a z-statistic. (Round your answer for part (a) to three decimal places.) (a) x = 195, u= 190, s = 21, n = 4 standardized statistic = it's t because s is used instead of o v (b) x = 195,H= 190, o = 25, n = 4 standardized statistic = it's z because o is known (c) x = 168,H= 190, s = 22, n = 25 standardized statistic = : it's t because s is used instead of o

Suppose a company wants to determine the percentage of customers who shop online. How many customers should the company survey in order to be 92% confident that the estimated (sample) proportion is within 3 percentage points of the true population proportion of customers who shop online? z0.16 z0.08 z0.04 z0.02 z0.01 0.994 1.405 1.751 2.054 2.326

:) For each of the situations below, define the parameter (proportion or mean) and write the null and alternative hypotheses in terms of parameter values. Example: We want to know if the proportion of up days in the stock market is 50%. Answer: Let p the proportion of up days. Ho: p = 0.5 vs. HA P# 0.5. : (a) Last year, customers spent an average of $45.82 per visit to the company's website. Based on a random sample of purchases this year, the company wants to know if the mean this year has changed. Let (p, p, μ, or x)= the of customer spending per visit to the website. ; HA Ho: (b) A pharmaceutical company wonders if their new drug has a cure rate lower than the 30% reported by the placebo. Let Ho: (p, p, μ, or )= the ; HA: Ho: of patients cured by the new drug. (c) A bank wants to know if the percentage of customers using their website has changed from the 40 % that used it before their system crashed last week. Let (p, p, μ, or ) the ; HA: of customers using the bank website.

Suppose a researcher wants to estimate the population proportion of defective light bulbs. He took a random sample of 800 light bulbs and 40 of them found out to be defective.  Suppose the researcher claims that the defective proportion of light bulb is less than 7%. Suppose he wants to test this claim at 5% significance level.   Calculate the test statistics. (Round your answer to two decimal places )