A random sample of 25 people is surveyed, and it was found that they spent an...

A random sample of 25 people is surveyed, and it was found that they spent an average of 32 hours a week watching TV. The standard deviation of their sample was 6 hours.

(a) Calculate a 95% confidence interval for the average number of hours spent watching TV per week (population mean µ - using two-tailed distribution).

(b) What is the 95% confidence interval for the single 26^th person to be surveyed?

(c) What is the 95% confidence interval (two-sided interval) such that at least 90% of the values in the population are inside this interval?

(d) What is a 95% confidence for the population variance σ²?

Expert Solution

------------------------------------------------------------------------------------------------------

orchestra answered 2 years ago

A random sample of 25 CCRI students found that the average amount spent on textbooks for...

A random sample of 25 CCRI students found that the average amount spent on textbooks for a course was $180 with a standard deviation of $30. Find a 95% 2-tailed confidence interval for the population mean (μ) of the amount a CCRI student spends on textbooks.

8. If a simple random sample of 215 students was surveyed, and it was found that...

8. If a simple random sample of 215 students was surveyed, and it was found that 90 of them have iPhones, what is the 90% confidence interval estimate of the proportion of all students who have iPhones?

9.9. Is gender independent of education level? A random sample of people was surveyed and each...

9.9. Is gender independent of education level? A random sample of people was surveyed and each person was asked to report the highest education level they obtained. Perform a hypothesis test. Include all 5 steps. High School Bachelors Masters Female 30 60 54 Male 25 40 44 10.9. Compute and interpret the correlation coefficient for the following grades of 6 students selected at random. Mathematical Grade 70 92 80 74 65 83 English Grade 74 84 63 87 78 90

9. In a random sample of males, it was found that 25 write with their left...

9. In a random sample of males, it was found that 25 write with their left hands and 223 do not. In a random sample of females, it was found that 74 write with their left hands and 436 do not. Use a 0.01 significance level to test the claim that the rate of left-handedness among males is less than that among females. Complete parts (a) through (c) below. a. Test the claim using a hypothesis test. Consider the first...

In a random sample of males, it was found that 25 write with their left hands...

In a random sample of males, it was found that 25 write with their left hands and 223 do not. In a random sample of females, it was found that 68 write with their left hands and 442 do not. Use a 0.01 significance level to test the claim that the rate of left-handedness among males is less than that among females. Complete parts (a) through (c) below. (a.) Test the claim using a hypothesis test. Consider the first sample...

6) In a random sample of males, it was found that 25 write with their left...

6) In a random sample of males, it was found that 25 write with their left hands and 209 do not. In a random sample of females, it was found that 75 write with their left hands and 454 do not. Use a 0.01 significance level to test the claim that the rate of left-handedness among males is less than that among females. Complete parts (a) through (c) below. a1) Test the claim using a hypothesis test Consider the first...

3. In 2000, a sample of 209 people aged 18-30 found that they spent an average...

3. In 2000, a sample of 209 people aged 18-30 found that they spent an average of 6.75 hrs/week on the internet. In 2006, a sample of 541 people aged 18-30 spent an average of 7.34 hrs/week on the internet. Has the average increased? Use correct notation where appropriate. For each of the following situations, a) What is/are the population(s) in the study? b) Does the scenario involve 1 or 2 parameters to be estimated/tested/compared? c) What is/are the parameter(s)...

In 1990 a random sample of 136 people surveyed showed that 39 were vegetarians. In 2015...

In 1990 a random sample of 136 people surveyed showed that 39 were vegetarians. In 2015 a similar survey showed that in a random sample of 95 people, 36 were vegetarians. Test the claim that the proportion of people that are vegetarians has changed. Use a 5% level of significance Ho: H1: Statistic: Conclusion:

2. A random sample of 395 people were surveyed and each person was asked to report...

2. A random sample of 395 people were surveyed and each person was asked to report the highest education level they obtained. The data that resulted from the survey is summarized in the following table: High School Bachelors Masters Ph.d. Total Female 60 54 46 41 201 Male 40 44 53 57 194 Total 100 98 99 98 395 a. Are gender and education level dependent at 5% level of significance? (6mks) b.State and explain two methods of studying...

Is gender independent of education level? A random sample of 395 people were surveyed and each...

Is gender independent of education level? A random sample of 395 people were surveyed and each person was asked to report the highest education level they obtained. The data that resulted from the survey is summarized in the following table: High School Bachelors Masters Ph.d. Total Female 60 54 46 41 201 Male 40 44 53 57 194 Total 100 98 99 98 395 Question: Are gender and education level dependent at 5% level of significance? In other words, given...

Question