statistics
posted by jr .
Lorraine was in a hurry when she computed a confidence interval for μ. Because σ was not known, she used a Student's t distribution. However, she accidentally used degrees of freedom n instead of n  1. Will her confidence interval be longer or shorter than one found using the correct degrees of freedom n  1? Explain.

Shorter. As the degrees of freedom increase, the value for tc decreases.
Respond to this Question
Similar Questions

statistics
Ok, so I'm trying to do this for my exam review. I get some of it, but not all: An electric utility is examining the relationship between temperature and electricity use in its service region on warm days. The utility has bivariate … 
statistics
a simple random sample of size n=5 is obtained from the population of drivers living in New York City, and the breaking reaction time of each driver is measured. The results are to be used for constructing a 95% confidence interval. … 
statistics
Consider a 90% confidence interval for μ. Assume σ is not known. For which sample size n=10 or n=20, is the confidence interval longer? 
statistics
Lorraine was in a hurry when she computed a confidence interval for . Because was not known, she used a Student's t distribution. However, she accidentally used degrees of freedom n + 1 instead of n  1. v Will her confidence interval … 
Statistics
When estimating a population mean μ, where the population standard deviation σ is known, we can: a. choose a larger z value, construct a wider confidence interval, and achieve a lower confidence level b. choose a smaller … 
statistics
Suppose we take a random sample of size n from a normal population with variance, σ2 . It can be shown that (n−1)s2/σ2 has a chisquare distribution with n−1 degrees of freedom, where s is the sample variance. … 
Statistics
Suppose x has a moundshaped distribution with sigma = 9 . A random sample of size 36 has sample mean 20. Is it appropriate to use a normal distribution to compute a confidence interval for the population mean m? 
Statistics
The standard deviation for a population is σ = 15.3. A sample of 36 observations selected from this population gave a mean equal to 74.8. a) Make a 90% confidence interval for μ b) Construct a 95% confidence interval for … 
statistics
Suppose x has a normal distribution with mean μ = 35 and standard deviation σ = 9. (a) Describe the distribution of x values for sample size n = 4. (Use 2 decimal places.) μx = σx = (b) Describe the distribution … 
Statistics
Suppose that a SRS of 900 12thgraders has x̅ =148. Based on this sample, a 95% confidence interval for μ is?