Additional Attachment

Math 21 Online – Practice Final • For sample size problems, just state the appropriate sample size. • For confidence interval problems, express your answer in a sentence. • For hypothesis tests, use the standard 5-step procedure.

1. Ho & H1 2. alpha 3. test 4. test statistic & p-value 5. Decision about Ho and conclusion

1) A news agency is planning a poll. The agency wants to determine what proportion of American citizens supported NATO involvement in Kosovo. If the agency wants to be 95% sure that the sample proportion differs from the true population proportion by no more than 4%, how large of a sample is necessary?

2) A high school counselor wants to estimate the mean SAT combined score for high school students. He has been told that the standard deviation for all such scores is approximately 230 points. How large of a sample is required in order to be 99% sure that his sample mean is off by no more than 10 points from the true mean SAT combined score.

3) A sample of 350 Americans were asked if they had ever seen a UFO, and 14 said that they had. Construct an 84% confidence interval for the proportion of all Americans who have seen a UFO.

4) Here are the ages of a random sample of 10 men who first married in 1998.

28 25 18 18 19 34 21 25 24 24

Construct a 95% confidence interval for the mean age at which men get married.

5) A sample of 340 Americans were asked whether they thought that UFO’s are real, and 146 said that they thought that UFO’s are real. At the 0.05 level of significance, test the claim that less than half of all Americans think that UFO’s are real.

6) A random sample of 36 COS students revealed that 10 of them owned an iPhone. At the 0.05 level of significance test the claim that less than 40% of COS students own an iPhone.

7) A random sample of 23 symphony musicians was asked how many hours they practiced their instrument per week. The survey produced a mean practice time of 6.2 hours with a standard deviation of 2.36 hours per week. At the 0.05 level of significance, test the claim that the mean time that symphony musicians practice per week is greater than 5 hours per week.

8) An experimental math exam was given to 8 students. Test the claim that the mean score is above 70 at the 0.05 level of significance.

64 77 85 78 81 89 79 80

9) The Harris Poll conducted a survey in which they asked, “How many tattoos do you currently have on your body?”

• Of the 1205 males surveyed, 181 responded that they had at least one tattoo. • Of the 1097 females surveyed, 143 responded that they had at least one tattoo.

Test the claim that the proportion of males that have at least one tattoo is different than the proportion of females that have at least one tattoo, at the 0.05 level of significance. 10) A random sample of 25 COS students had 16 female students. A random sample of 100 Fresno State students had 52 female students. At the 0.05 level of significance, test the claim that the proportion of female students at COS is higher than it is at Fresno State.

11) To test the belief that sons are taller than their fathers, a student randomly selects 13 fathers who have adult male children. She records the height of both the father and son in inches and obtains the following data. Test the claim that sons are taller than their fathers at the 0.05 level of significance.

Family 1 2 3 4 5 6 7 8 9 10 11 12 13 Father 70.3 67.1 70.9 66.8 72.8 70.4 71.8 70.1 69.9 70.8 70.2 70.4 72.4 Son 74.1 69.2 66.9 69.2 68.9 70.2 70.4 69.3 75.8 72.3 69.2 68.6 73.9

12) A random sample of 9 Math 200 students took a practice final exam one week before their final exam. Use the data to test the claim that students improve their scores from the practice test to the actual exam at the 0.05 level of significance.

Student 1 2 3 4 5 6 7 8 9 Practice 74 70 85 81 76 90 65 84 52 Final 71 81 98 90 84 99 78 91 61

13) Do people walk faster in the airport when they are departing (getting on a plane) or when they are arriving (getting off a plane)? A researcher measured the walking speed of travelers in two airports.

• 35 departing passengers had a mean walking speed of 260 feet/minute, with a standard deviation of 53 feet/minute.

• 35 arriving passengers had a mean walking speed of 269 feet/minute, with a standard deviation of 34 feet/minute.

Test the claim that the mean walking speed for departing passengers is different than the mean walking speed for arriving passengers at the 0.05 level of significance.

14) A student wants to test the claim that male college students are taller than female college students at the 0.05 level of significance. Here are the heights, in inches, of randomly selected college students. Male 74 71 75 72 70 82 Female 68 66 64 63 69 65 70 60

15) A geneticist claims that one parent with brown eyes and a second parent with green eyes will produce offspring with the following eye-color distribution: 50% brown, 37.5% green, 12.5% blue. Here are the eye colors of 200 children that have one parent with brown eyes and one parent with green eyes.

Color Brown Green Blue Frequency 112 70 18

Test the geneticist’s claim at the 0.05 level of significance. 16) Does a person’s gender influence their ice cream preference? A random sample of individuals were asked to name their favorite ice cream flavor. Here are the results, broken down by gender.

Chocolate Vanilla Other Male 80 30 90 Female 40 90 70

Test the claim that ice cream preference is independent of gender at the 0.05 level of significance.

17) Here are the waiting times, in minutes, at the check-in counters for four different airlines at an airport for randomly selected fliers.

Airline A Airline B Airline C Airline D 3 19 8 7

11 13 11 16 19 11 17 15 11 13 7 9 7 12

10 At the 0.05 level of significance, test the claim that the mean waiting time at the checkout counters of the four airlines are equal.

18) Here are the ages of randomly selected students in Math 200, Math 230, and Math 21. Use the data to test the claim that the mean age of all students in those three classes are equal. Use α = 0.05.

Math 200 18 35 22 46 24 18 20 Math 230 19 20 22 18 25 Math 21 21 19 20 22 18 18 18 19