Question

A random sample of 121 checking accounts at a bank showed an average daily balance of...

A random sample of 121 checking accounts at a bank showed an average daily balance of $280. The standard deviation of the population is known to be $66. Construct a 95% confidence interval estimates for the mean. (Round to two decimal places) [Answer , Answer ] Construct a 99% confidence interval for the mean. (Round to two decimal places) [Answer , Answer ]

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

Homework Answers

Answer #1

We have given that,          
          
Sample mean =$280  
Population standard deviation=$66
Sample size=121  
          
i) 95% confidence interval
Z critical value=1.96  
          
Confidence interval formula is

          
Lower confidence limit =$268.24
Upper confidence limit =$291.76

ii) 99% confidence interval


Z critical value=2.58  
          
Confidence interval formula is

Lower confidence limit =$264.52
Upper confidence limit =$295.48

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
Wachovia Bank has 800 checking account customers. A recent sample of 60 of these showed 35...
Wachovia Bank has 800 checking account customers. A recent sample of 60 of these showed 35 to have a Visa card with the bank. Construct the 99% confidence interval for the proportion of checking account customers who have a Visa with the bank. b. What sample size would be needed if you want the estimated proportion to be within 4% of the population proportion at the 99% confidence level? if possible draw distributions? Thanks in advance
A random sample of 100 credit sales in a department store showed a sample mean of...
A random sample of 100 credit sales in a department store showed a sample mean of $64. The population standard deviation is known to be $16. A) Provide a 99% confidence interval for the population mean. B) Provide a 95% confidence interval for the population mean. C) Describe the effect of a lower confidence level on the margin of error.
The First National Bank of Wilson has 660 checking account customers. A recent sample of 60...
The First National Bank of Wilson has 660 checking account customers. A recent sample of 60 of these customers showed 35 have a Visa card with the bank. Construct the 99% confidence interval for the proportion of checking account customers who have a Visa card with the bank. (Use z Distribution Table.) (Round your answers to 3 decimal places.) Confidence interval for the proportion is between and
The First National Bank of Wilson has 740 checking account customers. A recent sample of 50...
The First National Bank of Wilson has 740 checking account customers. A recent sample of 50 of these customers showed 27 have a Visa card with the bank. Construct the 99% confidence interval for the proportion of checking account customers who have a Visa card with the bank. (Use z Distribution Table.) (Round your answers to 3 decimal places.)
A sample of 64 account balances from a credit company showed an average daily balance of...
A sample of 64 account balances from a credit company showed an average daily balance of $1,040. The standard deviation of the population is known to be $200. We are interested in determining if the mean of all account balances (i.e., population mean) is significantly different from $1,000. a. Develop the appropriate hypotheses for this problem. b. Compute the test statistic. c. Compute the p-value. d. Using the p-value approach at 95% confidence, test the above hypotheses. e. Using the...
The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The...
The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The daily balance of a checking account is defined to be the balance in the checking account at 2:00pm. The bank has found that for all personal checking accounts the mean of all the daily balances is $700 and the standard deviation is $200. In addition, the distribution of personal checking account daily balances can be approximated very well with a normal model. Question 1....
The mean balance of all checking accounts at a bank on December 31, 2009, was $850....
The mean balance of all checking accounts at a bank on December 31, 2009, was $850. A random sample of 55 checking accounts taken recently from this bank gave a mean balance of $780 with a standard deviation of $230. Using the 1% significance level, can you conclude that the mean balance of such accounts has decreased during this period? Answer this question by following the p-value approach.
A savings and loan association needs information concerning the checking account balances of its local customers....
A savings and loan association needs information concerning the checking account balances of its local customers. A random sample of 14 accounts was checked and yielded a mean balance of $664.14 and a standard deviation of $297.29. Find a 95% confidence interval for the true mean checking account balance for local customers. Use the given degree of confidence and sample data to construct a confidence interval for the population mean μ. Assume that the population has a normal distribution. Round...
The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The...
The First Chicago Bank is reviewing its service charges and interest-paying policies on checking accounts. The daily balance of a checking account is defined to be the balance in the checking account at 2:00pm. The bank has found that for all personal checking accounts the mean of all the daily balances is $900 and the standard deviation is $125. In addition, the distribution of personal checking account daily balances can be approximated very well with a normal model. QUESTION: What...
The First National Bank of Wilson has 720 checking account customers. A recent sample of 60...
The First National Bank of Wilson has 720 checking account customers. A recent sample of 60 of these customers showed 22 have a Visa card with the bank. Construct the 98% confidence interval for the proportion of checking account customers who have a Visa card with the bank. (Use z Distribution Table.) (Round your answers to 3 decimal places.) Confidence interval for the proportion is between  and .
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT