Question

1.      A questionnaire of spending habits was given to a random sample of college students. Each...

1.      A questionnaire of spending habits was given to a random sample of college students. Each student was asked to record and report the amount of money they spent on books and school supplies in a semester. The amount of money spent on books and school supplies is said to follow normal distribution. The sample of 85 students resulted in an average of $850.  

a)     What are the simple conditions necessary for the confidence interval to be valid?

b)     Find and interpret a 96% confidence interval for the mean amount of money spent by college students on books and school supplies if the population standard deviation is $140.

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

a) The simple conditions necessary for the confidence interval to be valid are

i) Samples are independent

ii) Samples are taken from normal population

iii) Sample mean is follows Normal distribution

b)

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A questionnaire about study habits was given to a random sample of students taking a large...
A questionnaire about study habits was given to a random sample of students taking a large introductory stats class. The sample of 35 students reported that they spent an average of 115 minutes per week studying stats. Assume that the standard deviation is 40 minutes. A) Give a 95% confidence interval for the mean time spent studying stats by students in this class. B) Is it true that 95% of the students in the class have weekly studying times that...
In an simple random sample of 200 college students, 114 said that they usually speed on...
In an simple random sample of 200 college students, 114 said that they usually speed on interstate highways by 10 mph or more. Give a 95% confidence interval for the corresponding proportion for all college students. a: (0.5014,0.6455) b: (0.5431,0.6386) c: (0.3567,0.4533) d: (0.5014,0.6386)
In a study about how much College students sleep at night, a sample of 25 students...
In a study about how much College students sleep at night, a sample of 25 students was selected. The sample average mean number of hours of sleep was 6.64 and the sample standard deviation was 1.075. (a) Construct a 90% confidence interval for the true mean number of hours of sleep at night College students get. (b) Interpret the interval. (c) What assumptions must be satisfied for the interval obtained in part (a) to be statistically valid?
5) Suppose that simple random samples of college freshman are selected from two universities, 25 students...
5) Suppose that simple random samples of college freshman are selected from two universities, 25 students from school A and 20 students from school B. On a standardized test, the sample from school A has an average score of 1010 with a standard deviation of 100. The sample from school B has an average score of 990 with a standard deviation of 90. a) What is the 90% confidence interval for the difference in test scores at the two schools?...
Show all work. Check your work with a calculator. Researchers are interested in understanding the weekend...
Show all work. Check your work with a calculator. Researchers are interested in understanding the weekend spending habits of college students. A simple random sample of 1500 college students is taken from universities across the United States. The average amount of money spent on the weekends was $95 with a standard deviation of $185. Construct a 95% confidence interval for the spending habits of college students on the weekends. Interpret your results. Round to the nearest hundredths. Researchers are interested...
Is college worth it? Among a simple random sample of 341 American adults who do not...
Is college worth it? Among a simple random sample of 341 American adults who do not have a four-year college degree and are not currently enrolled in school, 154 said they decided not to go to college because they could not afford school. 1. Calculate a 95% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it, and interpret the interval in context. Round to 4 decimal places. (_,_) 2. Suppose...
Is college worth it? Among a simple random sample of 334 American adults who do not...
Is college worth it? Among a simple random sample of 334 American adults who do not have a four-year college degree and are not currently enrolled in school, 157 said they decided not to go to college because they could not afford school. 1. Calculate a 90% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it, and interpret the interval in context. Round to 4 decimal places. ( , )...
Is college worth it? Among a simple random sample of 334 American adults who do not...
Is college worth it? Among a simple random sample of 334 American adults who do not have a four-year college degree and are not currently enrolled in school, 144 said they decided not to go to college because they could not afford school. 1. Calculate a 99% confidence interval for the proportion of Americans who decide to not go to college because they cannot afford it, and interpret the interval in context. Round to 4 decimal places. ( ,  ) 2....
1. A random sample of 429 college students was interviewed about a number of matters. For...
1. A random sample of 429 college students was interviewed about a number of matters. For each of the below, write a sentence summarizing the results (i.e “I am 95% confident that….”) a. They reported that they had spent an average of $378.23 on textbooks during the previous semester. If the sample standard deviation for these data is $15.78, construct an estimate of the population mean at the 95% confidence level. b. They also reported that they had visited the...
The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation,...
The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitude toward school, and study habits of students. Scores range from 0 to 200. A selective private college gives the SSHA to a simple random sample of both male and female first-year students to study the difference in mean attitudes towards school and study habits between men and women. The data for men and women: n s Men 20 121.3 32.85 Women 18 141.1...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT