The owners of an industrial plant want to determine which of two types of fuel (gas or electricity) will produce more useful energy at a lower cost. The cost is measured by plant investment per delivered quad ($ invested per quadrillion BTUs). The smaller the number, the less the industrial plant pays for delivered energy. Random samples of 11 similar plants using electricity and 16 similar plants using gas were taken, and the plant investment per quad was calculated for each. In an analysis of the difference of means of the two samples, the owners were able to reject H, in the test Ho: He - He =0 vs H: He -He > 0. What is the best interpretation of the result? O A The mean investment per quad for electricity is less than the mean investment per quad for gas. O B. The mean investment per quad for electricity is different from the mean investment per quad for gas. O C. The mean investment per quad for electricity is greater than the mean investment per quad for gas. O D. The mean investment per quad for electricity is not different from the mean investment per quad for gas.

A police academy has just brought in a batch of new recruits.  All recruits are given an aptitude test and a fitness test. Suppose a researcher wants to know if there is a significant difference in aptitude scores based on a recruits’ fitness level. Recruits are ranked on a scale of 1 – 3 for fitness (1 = lowest fitness category, 3 = highest fitness category). Using “ApScore” as your dependent variable and “FitGroup” as your independent variable, conduct a One-Way, Between Subjects, ANOVA, at α = 0.05, to see if there is a significant difference on the aptitude test between fitness groups.    Identify the correct symbolic notation for the alternative hypothesis.    A. H0: µ1 = µ2 B. HA: µ1 ≠ µ2 ≠ µ3 C. H0: µ1 = µ2 = µ3 D. HA: µ1 ≠ µ2

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents.x  12.3 28.6  24.5 14.3  7.5   27.7 16.2 20.1y   23   72     39      23    15    30    15    25   a) Compute r. (Round your answer to four decimal places.)

Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents. x 10.9 30.4 24.5 14.3 7.5 27.7 16.2 20.1 y 23 76 39 23 15 30 15 25   (a) Make a scatter diagram of the data. Then visualize the line you think best fits the data. A scatter diagram has a horizontal axis labeled "x (student enrollment (in thousands))" with values from 7.5 to 30.4 and a vertical axis labeled "y (annual number of burglaries)" with values from 15 to 76. The scatter diagram has 8 points. A pattern goes up and…

A researcher is studying two types of medication that both treat hives. 23 out of the random sample of 270 adults given medication A still had hives 30 minutes after taking the medication. 15 out of another random sample of 300 adults given medication B still had hives 30 minutes after taking the medication. Test to see if the proportion of people who still had hives after medicine A is different than the proportion of people who still had hives after medicine B. Use a 0.01 level of significance. The correct hypotheses are: Ho:PA PB (claim) Ho :PA PB H A:PA < PB (claim) Но :РА На :РА # рв (claim) = PB Since the level of significance is 0.01 the critical value is 2.576 and -2.576 The test statistic is: 1.684 x (round to 3 places) The p-value is: 0.092 x (round to 3 places) The decision can be made to:

Prices of diamonds are very sensitive to their weight (measured in carat). For example, the price of a 1 carat diamond tends to be much higher than the price of a 0.99 carats diamond. To study this phenomenon in more detail, we consider two random samples of diamonds, 0.99 carats and 1 carat, each sample of size 23. The average price of 0.99 carats diamonds in the sample is $4451, while the average price of 1 carat diamonds in the sample is $5681. From long-term studies, we know that both the prices of 0.99 carats diamonds and the prices of 1 carat diamonds are normally distributed with standard deviations oj = $1332 (0.99 carats) and o2 = $1613 (1 carat), respectively. (a) Carry out a hypothesis test at significance level 0.01 to evaluate whether the true average price µi of 0.99 carats diamonds is lower than the true average price µ2 of 1 carat diamonds. Specify Ho and Ha, the test statistic, and calculate the p-value or use p-value considerations to conclude. (b) Compute the type II…