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morganc_z41
Dec 7, 2013, 01:22 PM
Find the appropriate confidence interval for the population proportion in each problem below. Please show all work necessary to get each confidence interval. Clearly identify, for each problem, the POINT ESTIMATE and the MARGIN OF ERROR. Be sure to see if your sample size is sufficiently large to actually construct the confidence interval.

1. When 425 junior college students were surveyed, 190 said they have a passport. Construct a 95% confidence interval for the proportion of junior college students that have a passport.

2. A survey of 700 non-fatal accidents showed that 272 involved uninsured drivers. Construct a 99% confidence interval for the proportion of fatal accidents that involved uninsured drivers.

3. In a survey of 10 musicians, 2 were found to be left-handed. Is it practical to construct the 90% confidence interval for the population proportion, p? Explain.

4. A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial aid. Use a 99% confidence interval to estimate the true proportion of students on financial aid.

Find the appropriate confidence interval for the population mean in each problem given below. Be sure to show ALL of your work necessary to arrive at your final answers. Your samples are all assumed to come from a normal population (including problem 8).

5. 1) How much money does the average professional hockey fan spend on food at a single hockey game? That question was posed to 10 randomly selected hockey fans. The sampled results show that sample mean and standard deviation were $19.00 and $3.35, respectively. Use this information to create a 98% confidence interval for the mean. Assuming that the population is normally distributed.

6. Construct a 90% confidence interval for the population mean, μ. Assume the population has a normal distribution. A sample of 15 randomly selected math majors has a grade point average of 2.86 with a standard deviation of 0.78.

7. Construct a 95% confidence interval for the population mean, μ. Assume the population has a normal distribution. A sample of 25 randomly English majors has a mean test score of 81.5 with a standard deviation of 10.2.

8. A random sample of 10 parking meters in a resort community showed the following incomes for a day. Assume the incomes are normally distributed. Find the 95% confidence interval for the true mean. Here are the sample values:
$3.60 $4.50 $2.80 $6.30 $2.60 $5.20 $6.75 $4.25 $8.00 $3.00

joypulv
Dec 7, 2013, 01:53 PM
You have 8 problems, all about the same math concept, and you are told to show all the calculations you used to get answers... so no one can do this for you. Were you not in class to study confidence intervals?