Researchers conducted a study to evaluate the effectiveness of three alcohol treatment programs. The researchers randomly assigned each of the 15 patients to receive one of these treatments. Sixty days later, the researchers measured the effectiveness of the program. One of their measures was the patient’s self-reported need to use alcohol. It was measured on a scale of 1 (low need) to 10 (high need). Test the null hypothesis that the patient’s self-reported need to use alcohol does not differ by type of treatment. Write a concluding statement. Treatment A Treatment B Treatment C 8 6 6 10 5 5 10 10 2 8 2 2 10 4 1

Attractiveness of body types has been a large discussion relating to effects on youth and culture. Unhealthy levels of BMI are often associated with beauty. A researcher decided to study how young heterosexual adults body type preferences related to BMI. Participants were asked to use a computer program to design their desired partner. The program then calculated the BMI of the designed partners. The table summarizes the results based on a SRS of 35 men and 48 women.   BMI designed by men n=35 x-bar=18.850 stdev=1.750 SE Mean 0.277 BMI designed by women n=48 x-bar=25.860 stdev=4.215 SE Mean 0.625 Use this information to conduct a test to decide if male and/or female body type preferences are associated with healthy BMI measurements. You should have two complete tests here. You may assume the populations are normally distributed.

A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo. Participants are randomly assigned to receive the new treatment or a placebo and the outcome is pain relief within 30 minutes. Of the 200 participants who received the new medication, 75 reported pain relief, while 60 out of the 200 participants who received the placebo reported pain relief. Is there a significant difference in the proportions of patients reporting pain relief? Run the test at a 5% level of significance. Give each of the following to receive full credit: 1) the appropriate null and alternative hypotheses; 2) the appropriate test; 3) the decision rule; 4) the calculation of the test statistic; and 5) your conclusion including a comparison to alpha or the critical value.

8q3r4 Group 1 Group 2 2358 2548 2382 2574 2683 2439 2489 2499 2640 2579 2572 2361 2713 2567 2676 2601 2666 2344

Researchers investigate how the presence of cell phones influence the quality of human interaction.  Subjects are randomly selected from a population and divided into an experimental group that is asked to leave their phones in the front of the room and a control group that are not asked to leave their cell phones at the front of the room.  Subjects are left alone for 10 minutes and then asked to take a survey designed to measure quality of interactions they had with others in the experiment.  What statistical test is appropriate?

Mental Health A study was performed looking at the effect of physical activity on cognitive function among adults at high risk for Alzheimer's disease. There were 170 eligible subjects randomly assigned to either an exercise intervention (exercise group) or a control intervention (control group). The subjects were followed at 6-month intervals up to 18 months of follow-up. The primary assessment scale was the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog). The results at 18 months of follow-up among participants with mild cognitive impairment are given in the table below. (Let population 1 be the exercise group and population 2 be the control group. Use exercise group control group.) Mean difference from baseline (18-month score minus baseline score) among participants with mild cognitive impairment in the ADAS-Cog score* Mean change 95% CI n H₁: Exercise group Control group USE SALT -0.37 (-1.37, 0.63) 48 -0.43 (-1.35, 0.49) 52 (a) What is the standard deviation of…

Dr. Mackintosh believes a new olfactory therapy would be more successful in promoting weight loss among obese patients. His patients are first weighed and then randomly assigned to olfactory therapy, dance therapy, or a control condition. At the end of the three weeks, the amount of weight lost is recorded. The results indicate no significant difference in the amount of weight lost between the three conditions. Identify the independent variable along with each level and the dependent variable.

Using the latest in medical technology, an orthopedic doctor has developed a new surgical procedure that he believes is an improvement over the standard procedure. He wants to study whether the mean recovery time of patients who have the new procedure is less than the mean recovery time of patients who have the standard procedure. The doctor studies a random sample of 11 patients who have the new procedure and a random sample of 9 patients who have the standard procedure. (These samples are chosen independently.) The doctor records each patient's recovery time (in days). The patients who had the new procedure have a sample mean recovery time of 367.3 with a sample variance of 2851.8. The patients who had the standard procedure have a sample mean recovery time of 420.9 with a sample variance of 98.1. Assume that the two populations of recovery times are approximately normally distributed. Can the doctor conclude, at the 0.01 level of significance, that the population mean of the…

Spam: A researcher reported that 71.8 % of all email sent in a recent month was spam. A system manager at a large corporation believes that the percentage at his company may be 69%. He examines a random sample of 500 emails received at an email server, and finds that 365 of the messages are spam. Can you conclude that greater than 69% of emails are spam? Use both a=0.01 and a= 0.05 levels of significance and the critical value method with the table. Part 1 of 5 State the appropriate null and alternate hypotheses. Ho: P- .69 H1: p> .69 This hypothesis test is a right-tailed V test. Part 2 of 5 Find the critical values. Round the answers to three decimal places. For a=0.01 , the critical value is 2.326 For a=0.05 , the critical value is 1.645 Part: 2/5 Part 3 of 5 Compute the test statistic. Do not round intermediate calculations. Round the answer to two decimal places.

Use the following information to answer the question.  A researcher wants to study different messaging platforms by collecting data on 40 individuals. Half of the individuals only use iMessage while the other half only use What's App. For the individuals who only used iMessage, they sent an average of 280 messages with a sample variance of 170 in the past week. For the individuals who only used What's App, they sent an average of 295 messages with a sample variance of 182 in the past week. Determine if there is a significant difference between the average messages sent between the two groups of individuals. Use a significance level of 1%. What is the null hypothesis? Group of answer choices A. The iMessage group on average sent more messages than the What's App group.   B. The iMessage group on average sent less messages than the What's App group.   C. There is no difference in the average number of messages sent between the two groups.   D. There is a difference in the average…