The following statistics represent crime rates per 1000 population for a random sample of 46 Denver neighborhoods. The mean crime rate, 64.2 and standard deviation, s 27.9 crimes per 1000 population a) Let us say that the data are representative of the population crime rates in Denver neighborhoods. (i) Compute the margin of error, E for an 80% confidence interval for u, the population mean crime rate for all Denver neighborhoods (i1) Compute an 80% confidence interval for u, the population mean crime rate for all Denver neighborhoods. b) Suppose you are advising the police department about police patrol assignments. One neighborhood has a crime rate of 57 crimes per 1000 population. Do you think that this rate is below the average population crime rate and that fewer patrols could safely be assigned to this neighborhood? Explain Use the confidence interval to justify your answer. c) Another neighborhood has a crime rate of 75 crimes per 1000 population average? Does this crime rate seem to be higher than the population average? Would you recommend assigning more patrols to this neighborhood? Explain. Use the confidence interval to justify your answer.

Traffic Highway planners investigated the relationshipbetween traffic Density (number of automobiles per mile)and the average Speed of the traffic on a moderately largecity thoroughfare. The data were collected at the samelocation at 10 different times over a span of 3 months.They found a mean traffic Density of 68.6 cars per mile(cpm) with standard deviation of 27.07 cpm. Overall, the cars’ average Speed was 26.38 mph, with standard devia-tion of 9.68 mph. These researchers found the regression line for these data to be Speed = 50.55 - 0.352 Density.a) What is the value of the correlation coefficientbetween Speed and Density?b) What percent of the variation in average Speed isexplained by traffic Density? c) Predict the average Speed of traffic on the thorough-fare when the traffic Density is 50 cpm. d) What is the value of the residual for a traffic Densityof 56 cpm with an observed Speed of 32.5 mph?e) The data set initially included the point Density =125 cpm, Speed = 55 mph. This…

Total blood volume (in ml) per body weight (in kg) is important in medical research.  For healthy adults, the red blood cell volume mean is about µ = 28 ml/kg with a standard deviation of 4.75ml/kg.  Red blood cells volume that is too low or too high can indicate a medical problem.    Suppose he does a hypothesis test with a significance level of 0.01.  Roger has had seven blood tests and the red blood cell volumes were: 32       25       41       35       30       37       29 Roger’s null hypothesis is that his blood tests are normal and that his alternative hypothesis is that something is wrong.  Symbolically, the null and hypotheses are as follows                         Ho: µ = 28 ml/kg and Hi: µ ≠ 28 ml/kg What value of the test statistic (z) should he report? (Sampling a Normal Distribution for the Mean µ)   Group of answer choices a. 0.99 b.2.42 c.2.62 d.2.22

Is there strong evidence of global warming? Let’s consider a small scale example, comparing how temperatures have changed in the US from 1968 to 2008. The daily high temperature reading on January 1 was collected in 1968 and 2008 for 51 randomly selected locations in the continental US. Then the difference between the two readings (temperature in 2008 - temperature in 1968) was calculated for each of the 51 different locations. The average of these 51 values was 1.1 degrees with a standard deviation of 4.9 degrees. We are interested in determining whether these data provide strong evidence of temperature warming in the continental US. (d) Calculate the test statistic and find the p-value. (e) What do you conclude? Interpret your conclusion in context. (f) Calculate a 90% confidence interval for the average difference between the temperature measurements between 1968 and 2008. Interpret this interval in context. (g) Does the confidence interval provide convincing evidence that the…