A city recently launched a neighborhood watch program to control crime. The following table gives the number of crimes reported in six neighborhoods during the six months before and six months after the city launched the neighborhood watch program. Before After O 3.365 O 3.747 57 73 49 71 79 39 41 65 28 73 61 32 Let the paired difference be the number of crimes before minus the number of crimes after the city launched the neighborhood watch program. The null hypothesis is that the mean of the population paired differences is equal to zero (i.e., the neighborhood watch program does not affect the number of crimes). The alternative hypothesis is that the mean of the population paired differences is greater than zero (i.e., the neighborhood watch program decreases the number of crimes). The significance level is 1%. What are the critical values of t for the hypothesis test?

The price of a share of stock divided by the company's estimated future earnings per share is called the P/E ratio. High P/E ratios usually indicate "growth" stocks, or maybe stocks that are simply overpriced. Low P/E ratios indicate "value" stocks or bargain stocks. A random sample of 51 of the largest companies in the United States gave the following P/E ratios†. 11 35 19 13 15 21 40 18 60 72 9 20 29 53 16 26 21 14 21 27 10 12 47 14 33 14 18 17 20 19 13 25 23 27 5 16 8 49 44 20 27 8 19 12 31 67 51 26 19 18 32   (a) Use a calculator with mean and sample standard deviation keys to find the sample mean x and sample standard deviation s. (Round your answers to four decimal places.)   x =   s =     (b) Find a 90% confidence interval for the P/E population mean ? of all large U.S. companies. (Round your answers to one decimal place.)   lower limit       upper limit         (c) Find a 99% confidence interval for the P/E population mean ? of all large U.S.…

Each of the digits in a raffle is thought to have the same chance of occurrence. The table shows the frequency of each digit for consecutive drawings in a California lottery. Perform the chi-square test to see if you reject the hypothesis at the 0.05 significance level that the digits are from a uniform population.  Digit Frequency Digit Frequency 0 43 5 46 1 41 6 39 2 45 7 40 3 41 8 39 4 47 9 29   Click here for the Excel Data File a. State the decision rule. Use 0.05 significance level. (Round your answer to 3 decimal places.) H0: The digits are uniformly distributed.H1: The digits are not uniformly distributed.  b. Compute the value of chi-square. (Round your answer to 3 decimal places.)

he accompanying data are x = advertising share and y = market share for a particular brand of cigarettes during 10 randomly selected years. x 0.103 0.073 0.071 0.077 0.086 0.047 0.060 0.050 0.070 0.052 y 0.132 0.126 0.122 0.086 0.079 0.076 0.065 0.059 0.051 0.039 (a) Calculate the equation of the estimated regression line. (Round your answers to six decimal places.)y =        Obtain the predicted market share when the advertising share is 0.09. (Round your answer to five decimal places.)(b) Compute r2. (Round your answer to three decimal places.)(c) Calculate a point estimate of ?. (Round your answer to four decimal places.)On how many degrees of freedom is your estimate based?

Three university administer the same comprehensive examination to the receipients of MS degree in Business Statistics. From each institution, a random sample of MS receipients was selected, and these receipients were then given to the exam.  The following tabel shows the scores of each student from the three universities Uni A                           Uni B                         Uni C    89.                               60.                            81  95.                                95.                            70  75                                 89                            90  92                                 80                           78  99                                 66 77  At a= 0.01 , test to see if there is a significant difference  in the average scores of students from the three universities Answer needed ASAP.

800 700 600 500 400 300 200 100 5 10 15 20 25 30 Twenty five high school students complete a preparation program for taking the SAT test. Here are the SAT scores from the 25 students who completed the SAT prep program: 34 457 53 720 400 484 610 641 425 454514 499 64 501 625 2 471 598 509 531 The mean of these scores is 536.00. We know that the population average for SAT scores is 500 with a standard deviation of 100. Using the scatterplot above, are there any outliers?

A chocolate store gives out small bags of chocolate to its customers, and each bag does not always have the same number of chocolate.  The following table represents a sample of a few bags showing the number chocolate of per bag.  Calculate IQR. Chocolate 18-20 21-23 24-26 27-29 30-32 33-35 36-38 39-41 Frequency 2 14 1 6 10 2 5 4

14. Sports Car: Fuel Injection The manufacturer of a sports car claims that the fuel injection system lasts 48 months before it needs to be replaced. A consumer group tests this claim by surveying a random sample of 10 owners who had the fuel injection system replaced. The ages of the cars at the time of replacement were (in months): LEGO 29 42 49 48 53 46 30 51 42 52 (i) Use your calculator to verify that the mean age of a car when the fuel injection system fails is x = 44.2 months, with standard deviation S=8.61months. (ii) Test the claim that the fuel injection system lasts less than an average of 48 months before needing replacement. Use a 5% level of significance. %3D

An educational researcher devised a wooden toy assembly project to test learning in 6-year-olds. The time in seconds to assemble the project was noted, and the toy was disassembled out of the child's sight. Then the child was given the task to repeat. The researcher would conclude that learning occurred if the mean of the second assembly times was less than the mean of the first assembly times. Child 1 2 3 4 6 7 Trial 1 100 150 150 110 130 120 118 Trial 2 90 130 150 06 105 110 120 a) At a = 0.01, can it be concluded that learning took place? b) At a = 0.10, can it be concluded that learning took place? c) Compare you answer for (a) and (b). d) Find the 98% confidence interval of the difference in means.

Solve the second one