In order to estimate the proportion of entering students who graduate within six years, the administration at a state university examined the records of 400 randomly selected students who entered the university six years ago, and found that 232 had graduated. Construct a 95% confidence interval for the population proportion of students who graduate within six years.

At one large college, 660 out of the 1500 students surveyed said they plan to take another science class.Find the 95% confidence interval for the proportion of students that said they plan to take another science class.

According to the U.S. Department of Transportation’s Air Travel Consumer Report, the nation’s 12 largest airlines recorded an on-time arrival percentage of 77.4% in 2001. Of interest is to estimate the mean delay time for the 22.6% of all flights that did not arrive on time during 2013. A simple random sample of 28 late arriving flights was selected, and the mean delay time of this sample of 28 flights was 14.2 minutes, with a sample standard deviation of s= 6.4 minutes. Use this information to calculate and interpret a 98% confidence interval for the mean delay time for all flights that did not arrive on time during 2013.

if n = 42, p = 0.6 then construct the 98% confidence interval for the population proportion.

If n=470 and p̂ (p-hat) = 0.65, construct a 95% confidence interval.

If n=17, ¯xx¯(x-bar)=50, and s=20, construct a confidence interval at a 98% confidence level. Assume the data came from a normally distributed population.

Identify the t score for a 99% confidence interval if the sample size is 35 t=

The dataset "nurses" is a random sample of 1,000 cases from “Health Care Provider Credential Data” from Washington State Open Data Portal. In the sample, there are 418 CNA's and 278 of the CNA's have expired credentials. Use the statistics from the nurses dataset to answer the following question: "With 90% confidence, what percent of all CNA's on Washington State's healthcare provider list are expired?"

A national research group reported that 36% of 18-24 year olds watch a cable news channel regularly.  The director of media relations at a large university wanted to know what proportion of students at her university who watch a cable news channel regularly. If it is less than 36%, then she will unsubscribe to the news channels.  She sampled 200 random students and found that 63 watched cable news regularly.     Should she conclude that proportion of students at her university who watch cable news regularly is less than 36% at the 8% significance level?    In the context of this problem and your conclusion, what type of error is possible?    In the context of this problem, what would the error be?    In the context of this problem, what would be a possible consequence of this error?

In the US, 45.9% of all people have type O blood, 39.7% have type A blood, 11.2% have type B blood and 3.2% have type AB blood. A researcher wants to see if the distribution of blood type is different for millionaires. The table below shows the results of a random sample of 569 millionaires. What can be concluded at the significant level of a = 0.01.   The test-statistic for this data =   The p-value for this sample =