Question

In: Statistics and Probability

Researchers are interested in determining if men and women’s hearts tend to be different sizes. In...

Researchers are interested in determining if men and women’s hearts tend to be different sizes. In a sample of 30 males, the mean diameter of the heart was 13.21 cm with a standard deviation of 1.05. Among 32 females, the mean diameter of the heart was found to be 11 cm with a standard deviation of 1.01. Construct a two-sided 95% confidence interval for the difference between the two means, assuming equal variance. Give an interpretation of the confidence interval.

Expert Solution

i am denoting male by 1 and female group by 2.

given data and necessary calculations are:-

the pooled estimate of standard deviation be:-

df = = ( 30+32-2) = 60

t critical value for df=60,alpha=0.05,both tailed test be:-

[ using t distribution table]

the 95% confidence interval for the difference between the two means is:-

interpretation:-

we are 95% confident that the true mean difference between men and women’s hearts sizes will be within 1.687 cm and 2.733 cm.

*** if you have any doubt regarding the problem please write it in the comment box.if you are satisfied please give me a LIKE if possible...

orchestra answered 1 year ago

Researchers interested in determining if there is a relationship between anxiety and religiosity conducted the following...

Researchers interested in determining if there is a relationship between anxiety and religiosity conducted the following study. Subjects completed a 5 point anxiety item (high score = high anxiety) and also completed a 15 item checklist designed to measure an individual’s degree of religiosity (belief in a particular religion, regular attendance at religious services, etc). A high score indicates greater religiosity. Sample data from 10 subjects are provided below. Can you predict anxiety (y) from religiosity (x)? First determine the...

Researchers for an advertising company are interested in determining if people are more likely to spend...

Researchers for an advertising company are interested in determining if people are more likely to spend more money on beer if advertisers put more beer ads on billboards in a neighborhood in Philadelphia. They estimate that 250 people will view their billboard in one week. They determine that the total number of residents in the neighborhood is 600. So, the residents who have not viewed the billboard are in the control group. The researchers determine that those who did view...

Men and women tend to choose different types of occupations, and so a. a source...

Men and women tend to choose different types of occupations, and so a. a source of wage differences between men and women is differences in human capital. b. a source of wage differences between men and women is compensating differentials. c. the gap between the earnings of men and the earnings of women is likely even more significant than the data alone indicate. d. we should expect the earnings of women to rise relative to the earnings of men,...

Researchers were interested in determining whether there was a difference in crime rates in areas where...

Researchers were interested in determining whether there was a difference in crime rates in areas where there is high youth unemployment vs low youth unemployment. Alpha (level of significance) was set at .05. State the null and alternate hypotheses. What is the independent variable? What is the dependent variable? Complete the table below: Low Youth Unemployment High Youth Unemployment Sample Size Sample Mean Sample Standard Deviation Estimated Standard Error Group Statistics High Youth Unemployment N Mean Std. Deviation Crime rate...

Researchers were interested in determining whether a new vaccine was better than the existing vaccine at...

Researchers were interested in determining whether a new vaccine was better than the existing vaccine at preventing HPV. This is an example of a a) clinical trial b) field trial c) community trial d) time trial

Researchers were interested in determining a new drug for reducing high blood pressure. They obtained a...

Researchers were interested in determining a new drug for reducing high blood pressure. They obtained a sample of volunteers for the study and randomly divided them into two groups, C and T. A single medical practitioner, Dr. Daring, agreed to help the researchers in this study following a protocol of three steps: (i) The blood pressure of each subject was measured by Dr. Daring; (ii) the new drug was administered to subjects in group T and a placebo to subjects...

Week 10 Assessment Background Researchers are interested in determining if a new diet program is effective...

Week 10 Assessment Background Researchers are interested in determining if a new diet program is effective at helping people lose weight. In a pilot study, the researchers collect a random sample of 10 subjects and measure their weight before beginning the diet, then again after one month on the diet program. Data The following table summarizes the information collected: Patient Weight Before (in lb) Weight After (in lb) Difference (After minus Before) Subject #1 207 202 -5 Subject #2 179...

Q1. Researchers were interested in determining whether there were any differences in the tendency to procrastinate...

Q1. Researchers were interested in determining whether there were any differences in the tendency to procrastinate based on birth order, i.e. first, second, or third child born. Using the data in the table below, answer the following questions. State the null and alternate hypotheses. What is the total sample size? Identify the independent and dependent variables What is the test statistic value? What is the p value? What is your conclusion (assume α = .05)? Phrase your conclusion based on...

Q4. Researchers were interested in determining whether gender and/or the number of tours soldiers served affected...

Q4. Researchers were interested in determining whether gender and/or the number of tours soldiers served affected the incidence of PTSD. The PTSD impact instrument was used and scores were recorded upon discharge. State the null and alternate hypotheses. Include both interaction and main effect hypotheses (should be 3 null and 3 alternate hypotheses). What is the total sample size? Identify the independent and dependent variables List the test statistic and p value for the all your hypotheses? (Hint, there should...

A survey on men and women’s shopping behavior collected data from a sample of 50 men...

A survey on men and women’s shopping behavior collected data from a sample of 50 men and 50 women. The following data on online shopping spending every month. Men Women 148 272 211 176 256 251 309 235 190 145 205 179 203 30 208 135 231 200 125 270 149 174 205 123 195 199 178 195 196 192 198 102 110 110 199 184 181 228 168 316 218 170 222 234 206 163 168 245 239 174...