A professor is interested in comparing the average amount, Ask an Expert

Statistics

A professor is interested in comparing the average amount spent on textbooks for freshmen and sophomores. A random sample of 9 freshmen yielded a sample mean amount of $1031 and a sample standard deviation of $58. A random sample of 9 sophomores yielded a sample mean amount of $1225 and a sample standard deviation of $313. Construct a 99% confidence interval for the difference between the mean amount spent on textbooks by freshmen and the mean amount spent by sophomores (ie. do freshmen minus sophomores). Since the sample standard deviations are wildly different, use a method which does not assume the populations have the same variance.

a) What is the appropriate degrees of freedom in this case? Give your answer to four decimal places.

b) What is the lower confidence limit on the interval? Give your answer to two decimal places.

c) What is the upper confidence limit on the interval? Give your answer to two decimal places.

View complete question

Statistics and Probability, Statistics

Category:- Statistics and Probability
Reference No.:- M9995161

Have any Question?Write your Review or question?

Related Questions in Statistics and Probability

50 of the cars in a dealer lot are red 20 are black and 16

50% of the cars in a dealer lot are red, 20% are black, and 16% are white. The remainder are some other unspecified color. Salespersons randomly shows three cars to three different customers. What is the probability the ...

The table to the right shows the results of a survey in

The table to the right shows the results of a survey in which 2575 adults from Country? A, 1126 adults from Country? B, and 1072 adults from Country C were asked if human activity contributes to global warming. Complete ...

A researcher records the following number of birdcalls made

A researcher records the following number of birdcalls made during an experimental session with robins: 8.4 0.9 (M SD). Assuming these data are normally distributed, what is the probability that robins made more than 11 ...

Gven that x is binomially distributed with n 36 and p

Given that X is binomially distributed with n = 36, and p = 0.33, use the normal approximation to the binomial (with correction for continuity) to estimate the probability that X is less than 14? Round your answer to 2 p ...

Discrete probability variablesthirtynbsppercent of

Discrete probability variables. Thirty percent of households say they would feel secure if they had? $50,000 in savings. You randomly select 8 households and ask them if they would feel secure if they had? $50,000 in sav ...

A calculus student takes a 20 question multiple choice test

A calculus student takes a 20 question multiple choice test with five answer choices for each question. Find the probability of getting atleast 70 percent of the question correct? Suppose a family has 5 children and that ...

In a management trainee program 80 of the trainees are

In a management trainee program 80% of the trainees are female, 20% male, A total of 90% of the females attended college, while 78% of the males attended college. A management trainee is selected at random. What is the p ...

You are working with a moe of -4 and a confidence level of

You are working with a MOE of +/-4% and a confidence level of 95%. P and Q =.50, and your CPI is $25.00. The company you work for needs to make a decision as to whether they may need different advertising for men and wom ...

The average or par score for an 18 hole golf course is

The average, or "par" score for an 18 hole golf course is 72. The score is computed by counting the number of swings, or "strokes" a player must make with their club to hit the ball into each of the 18 holes on the golf ...

A recent study found that 64 of workers between the ages of

A recent study found that 64?% of workers between the ages of? 20-29 cash out their retirement accounts when they lose their jobs or move to a new employer. Complete parts a through e below based on a random sample of 14 ...

4,153,160 Questions Asked
13,132 Experts
2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Recent Questions

Ask Statistics and Probability Expert