Suppose that it costs $3 to make one dose of the small pox vaccine. Once a dose is made, its shelf life is 90 days, after which it can no longer be used. It is desired to have, on average, 300 million doses available at any given time. (a) What is the yearly cost to implement this plan? (b) Suppose now that the shelf life of a vaccine is randomly distributed according to an Erlang distribution with a mean of 90 days and a standard deviation of 30 days. What is the yearly cost to implement this plan? 10 1:C

3. Suppose that the length of time Y to conduct a periodic maintenance check (from previous experience) on office copiers follows a gamma-type distribution with a = 3 and ß = 2. Suppose a new repairman requires 20 minutes to check a machine. Does it appear that his time to perform a maintenance check disagrees with prior experiences?

A manufacturer says that not only will 90% of their copiers last at least 36 months, 61% will last at least 42 months. If the copier lifetimes are normally distributed, what normal model parameters is this manufacturer claiming? [[ 36 is the 10th percentile 1.28 stdev below the mean [[ 42 is the 39th percentile 0.28 stdev below the mean [[ 36 = mean – 1.28 stdev [[ 42 = mean – 0.28 stdev [[ solve mean and stdev [[ mean = 43.68 and stdev = 6

Suppose that for a given treatment group, 40% are expected to have an asthma attack within the first year after enrolling in the study. The average hazard (i.e. rate of asthma attacks) during that time in that group is  60% 40% 0% 50%

Recent publications have addressed the growing concern in the scientific community around the increased prevalence of CAT scans in children between the ages of 7-18 and the growing rate of childhood cancers. Suppose the researcher plans to gather a SRS from a group of children in this age range who have received one or more CAT scans, and a SRS from a group of children who have never received a CAT scan and compare the number of cases of childhood cancers that develop over a prolonged period of time. Assume the following table summarizes the descriptive statistics for his samples. Population Average cases of childhood cancers Standard deviaton Sample size >CAT scan 24.6 2.4 1,894 No CAT scans 11.4 1.9 2,745 A) Carry out the appropriate statistical test to answer the researcher’s hypothesis regarding the difference in average cases of childhood cancers in children aged 7-18 receiving one or more CAT scans versus those that have never received a CAT scan. Use an alpha level…

Suppose you fit a simple Poisson model such that in A = XB where B = 1.9. What would the variance be if x = -0.8 ?

Suppose the incidence rate of influenza (flu) during the win-ter of 2008−2009 (i.e., from December 21, 2008, to March 20, 2009) was 50 events per 1000 person-months among students in high schools in a particular city. 14.32 A group of high-risk high school students was iden-tified in the winter of 2008−2009 who had 3+ previous episodes of influenza before December 21, 2008. There were 20 students in this group, each followed for 90 days, of whom 8 developed influenza. Test the hypothesis that the high-risk students had a higher incidence rate of influenza than the average high school student during the winter of 2008−2009. Report a one-tailed p-value. 14.33 Provide a two-sided 95% CI for incidence rate of flu among high-risk students during winter 2008−2009. Among 1200 students in one high school in the city, 200 developed a new case of influenza over the 90 days from December 21, 2009, to March 20, 2010. 14.34 What is the estimated incidence rate of flu in the 2009−2010 winter season…

Levi-Strauss Co manufactures clothing.  The quality control department measures randomly selected weekly values of different suppliers for the percentage difference of waste between the layout on the computer and the actual waste when the clothing is made (called run-up).  The data is in table #11.3.3, and there are some negative values because sometimes the supplier is able to layout the pattern better than the computer ("Waste run up," 2013). The population distributions are known to be normally shaped for each plant. Do the data show that there is a difference between some of the suppliers?  Test at the 1% level. The data is PLNT1, PLNT2, PLNT3, and PLNT4. A) Name of test B) Give the random variables and the parameter. C) State the null and alternative hypotheses and the level of significance. D) State and check the assumptions for the hypothesis test.  E) Find the test statistic and the p-value. F) Conclusion Attached is the data set.

A Stat 510 student works at the IT Help Desk at Hale Library. She works there Tuesdays and Thursdays 6 pm - 10 pm and on Sunday 1 pm - 5 pm. On average, she receives 2.4 walk-ins per shift on Tuesdays and Thursdays and 3.2 walk-ins on Sundays. Assume walk-in arrivals occur randomly at a constant rate, and different periods of time are independent. Assume that the proportion of walk-in problems that have a quick solution follows a Beta distribution. 1 Let rv. X = the time in hours until her fırst walk-in on a Tuesday shift. What is the distribution of X? Hint: How many hours are in a shift? a. X ~ Exp(0.6) b. Х Exp(2.4) c.X~ Gamma(4, 2.4) d. X~ Gamma(1, 2.4) e. X ~ Gamma(4,0.6) f.X ~ Gamma(1,0.6) g. None of the above. FORMULA. What is the probability that she will wait more than 3.0 hours for the first customer of a Sunday shift? (Use four digits after the decimal point, e.g., 0.1234) Type your answer. O O O O O0O

A large manufacturing company investigated the service it received from suppliers and discovered that, in the past, 32% of all materials shipments were received late. However, the company recently installed a just-in-time system in which suppliers are linked more closely to the manufacturing process. A random sample of 110 deliveries since the just-in-time system was installed reveals that 22 deliveries were late. Use this sample information to test whether the proportion of late deliveries was reduced significantly. Let a = 0.05. a) Show the verification that the sampling distribution of the proportion is normal. b) Follow the procedure for tests of hypothesis and use a 5% level of significance. Use the following hypotheses .. Ho: p = 0.32 %3D H1: p < 0.32