Portage Learning MATH 110 Final Exam completed with 100% answers

Portage Learning MATH 110 Final Exam Final Exam Question 1 Not yet graded / 10 pts You may find the following files helpful throughout the exam: The following pie chart shows the percentages of total items sold in a month in a certain fast food restaurant. A total of 4700 fast food items were sold during the month. a.) How many were fish? b.) How many were french fries? Your Answer: a. fish 4700(0.28)=1316 b. French fries 4700(0.4)=1880 a.) Fish : 4700(.28) = 1316 b.) French Fries: 4700(.40) = 1880 Question 2 Consider the following data: 392 410 Find the 40th percentile of this data. This study source was downloaded by from CourseH on :11:01 GMT -05:00 in ascending order: For the 40th percentile: Therefore, the 40th percentile index for this data set is the 6th observation. In the list above, the 6th observation is 407. Question 3 In a tri-state conference, 60% attendees are from California, 25% from Oregon, and 15% from Washington. As it turns out 6 % of the attendees from California, 17% of the attendees from Oregon, and 12% of the attendees from Washington came to the conference by train. If an attendee is selected at random and found to have arrived by train, what is the probability that the person is from Washington? P(Train│C)=.06.. P(Train│O)=.17.. P(Train│W)=.12.. P(C)=.60,P(O)=.25,P(W)=.15. We want to find P(W│Train), so use: Question 4 Find each of the following probabilities: a. Find P(Z ≤ -0.87) . b. Find P(Z ≥ .93) . c. Find P(-.59 ≤ Z ≤ -.36). a. P(Z ≤ -0.87)= .19215. b. P(Z ≥ .93)=1- .82381= .17619. This study source was downloaded by from CourseH on :11:01 GMT -05:00 P(-.59 ≤ Z ≤ -.36)= .35942- .27760= .08182. Question 5 Suppose that you are attempting to estimate the annual income of 1700 families. In order to use the infinite standard deviation formula, what sample size, n, should you use? In order to use infinite standard deviation formula, we should have: n≤0.05(1700) n≤85 So, the sample size should be less than 85. Question 6 A shipment of 450 new blood pressure monitors have arrived. Tests are done on 75 of the new monitors and it is found that 15 of the 75 give incorrect blood pressure readings. Find the 80% confidence interval for the proportion of all the monitors that give incorrect readings. Answer the following questions: 1. Multiple choice: Which equation would you use to solve this problem? A. B. C. This study source was downloaded by from CourseH on :11:01 GMT -05:00 E. 2. List the values you would insert into that equation. 3. State the final answer to the problem We have a finite population, so we will use Case 2: E. The proportion of the sample that are defective is 15/75 = .2 so we set P=.2. As we mentioned previously, we estimate p by P. So, p=.2. A total of 75 monitors were tested, so n=75. Based on a confidence limit of 80 %, we find in table 6.1 that z=1.28. The total number of monitors is 450, so set N=450. Now, we can substitute all of these values into our equation: .2± .054 So the proportion of the total that are defective is between .146 and .254. Question 7 It is recommended that pregnant women over eighteen years old get 85 milligrams of vitamin C each day. The standard deviation of the population is estimated to be 9 milligrams per day. A doctor is concerned that her pregnant patients are not getting enough vitamin C. So, she collects data on 40 of her patients and finds that the mean vitamin intake of these 40 patients is 83 milligrams per day. Based on a level of significance of α = .015, test the hypothesis. H0: μ=85 milligrams per day. H1: μ85 milligrams per day. This study source was downloaded by from CourseH on :11:01 GMT -05:00 find z.015 = -2.17. For a left-tailed test, we will reject the null hypothesis if the z-score is less than -2.17. Notice that since the z-score is greater than -2.17, we do not reject the null hypothesis. Question 8 Suppose we have independent random samples of size n1 = 570 and n2 = 675. The proportions of success in the two samples are p1= .41 and p2 = .53. Find the 99% confidence interval for the difference in the two population proportions. Answer the following questions: 1. Multiple choice: Which equation would you use to solve this problem? A. B. C. D. 2. List the values you would insert into that equation. 3. State the final answer to the problem This study source was downloaded by from CourseH on :11:01 GMT -05:00 greater than 30, so we may use eqn. 8.2: B. So, the interval is (-.1927,-.0473). Question 9 Compute the sample correlation coefficient for the following data: Can you be 95% confident that a linear relation exists between the variables? If so, is the relation positive or negative? Justify you answer. r= .9910 Sx = 4.2 Sy = 5.7. Note that for n=5 and 95% we get a value from the chart of .87834. The absolute of r is |r|=.9910, which is above .87834. So a positive linear relation exists. Question 10 A trucking company wants to find out if their drivers are still alert after driving long hours. So, they give a test for alertness to two groups of drivers. They give the test to 330 drivers who have just finished driving 4 hours or less and they give the test to 215 drivers who have just finished driving 8 hours or more. The results of the tests are given below. This study source was downloaded by from CourseH on :11:01 GMT -05:00 Drove 4 hours or less 250 80 Drove 8 hours or more 140 75 Is there is a relationship between hours of driving and alertness? (Do a test for independence.) Test at the 1 % level of significance. H0: Driving hours and alertness are independent events. H1: Driving hours and alertness are not independent events. We have two rows and three columns, so # of Rows =2 and # of Columns=2. The degrees of freedom are given by: DOF = (# of Rows-1)(# of Columns-1)=(2-1)(2-1)=1. Using this, along with .01 (for the 1% level of significance) we find in the chi-square table a critical value of 6.635. This value is greater than the critical value of 6.635. So, we reject the null hypothesis. This study source was downloaded by from CourseH on :11:01 GMT -05:00 Powered by TCPDF ()