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An automotive researcher wanted to estimate the difference required to come to a complete stop while traveling 40 miles per hour on wet versus dry pavement. Because car type plays a role, the researcher used eight different cars with the same driver and tires.  The braking distance (in feet) on both wet and dry pavement is shown in the table below. Conduct the appropriate hypothesis test to determine if the braking distance on the wet surface is longer from the braking distance on the dry surface. Use a 0.05 level of significance.  Note:  a normal probability plot of the data indicate that the differences are approximately normally distributed with no outliers.  This is a matched pairs problem.   Car 1 2 3 4 5 6 7 8 Wet 106 100 108 111 105 105 110 107 Dry 71 68 74 73 75 75 75 81   a. 

You want to estimate the mean cost of a new cell phone.  Find a 99% confidence interval for the average price of a cell phone after you find a sample of 21 phones that have a mean price of $1150 with a standard deviation of $225.  Round your answer to the nearest dollar. Lower bound: [answer1] Upper bound: [answer2]

Fill in the following table: Variable Continuous, Discrete or NA Nominal, Ordinal, Interval, Ratio Temperature  of a car to the nearest 10th of a degree [answer1] [answer5] Number of cars on a lot [answer2] [answer6] Brand of the car [answer3] [answer7] Size of the car (Small, medium,..) [answer4] [answer8]

Pass rates for Intermediate Algebra at a community college are 53.6%.  In an effort to improve the course, faculty of a community college develop a mastery-based learning model where course content is delivered is through a computer program.  The instructor serves as a learning mentor for the students in the course.  Of the 480 students who enrolled on the mastery-based course, 275 did pass.  At the 0.05 level of significance, decide whether the sample evidence suggests that the mastery-based learning model improved pass rates. a. What is your hypotheses (see above choices) b.  What is your test statistic? c.  What is your p-value or critical values and what is your conclusion? Briefly explain as in, I reject Ho because….. or I do not reject Ho because….. d.  Write a conclusion sentence in the context of the problem. e.  What type of error could you have made? Briefly explain.

If the 95% confidence interval for the mean cost of texts books per semester at a community college is between ($145, $645), what would be the appropriate conclusion sentence. a.  There is a 95% probability the mean cost of the textbooks at a community college are between $145 and $645. b.   We are 95% confident the mean cost of the textbooks at a community college are between $145 and $645. c.  There is a 95% chance the mean cost of the textbooks at a community college are between $145 and $645. d.   The the mean cost of the textbooks at a community college are between $145 and $645. Answer: [answer1]   Based on the above confidence interval would it be unusual for a student to spend $500 on textbooks for one semester at a community college? a.  No, because textbooks are expensive and who knows what you will spend. b.  Yes, because $500 is outside of the bounds for the 95% confidence interval and that would make spending $500 unusual. c.  No, because $500 is within of the bounds for the 95% confidence interval and that would make spending $500 usual. d.  Yes because $500 is within the bounds of the 95% confidence interval and that would make spending $500 unusual. Answer: [answer2]

Twelve jurors are randomly selected from a large population in which it is known that 85% are right handed. Assuming the jury has 12 members, find the following: (you may round your answers to 4 decimal places, no sentence necessary) a. Find the probability that exactly 6 are right handed. [answer1] b. Find the probability that at most 6 of them are right handed. [answer2] c. Find the probability that at least 6 of them are right handed.  [answer3]

An environmentalist wanted to determine of the mean acidity of rain differed among Alaska, Florida, and Texas.  18 randomly selected six rain dates of each of the three locations and obtained the following data: Alaska Florida Texas 5.41 4.87 6.46 5.39 5.18 6.89 4.90 4.52 6.57 5.14 5.12 4.15 4.80 4.89 4.45 5.24 5.06 4.30   Test whether the acidity of the rain is the same in the three cities, use a 0.05 significance level.  You may assume the requirements are met to run this test. a. What are the null and alternative hypotheses? b.  What is your test statistic? c.  What is your p-value or critical values and what is your conclusion? Briefly explain as in, I reject Ho because….. or I do not reject Ho because….. d.  Write a conclusion sentence in the context of the problem.

The purpose of Anterior Cruciate Ligament is to ________.

Describe the screw home mechanism and its purpose.