urchasing manager for a large university is investigating which brand of LCD projector to purchase to equip their classrooms. Of major concern is the gevity of the light bulbs used in the projectors. The purchasing manager has narrowed down the choice of projector to two brands, Infocus and Proxima, and shes to determine if there is any difference between the two brands in the mean lifetime of the bulbs used. e purchasing manager obtained eight projectors of each brand for testing over the last several academic terms. The number of hours the bulbs lasted on each the eight projectors is given in the table." Lifetimes of light bulbs (hours) Infocus 745, 955, 1085, 756, 901, 839, 858, 931 Proxima 1012, 988, 957, 920, 878, 1130, 657, 743 Send data to calculator Assume that the two populations of lifetimes are normally distributed and that the population variances are equal. Can we conclude, at the 0.01 level of significance, that H, the mean lifetime of light bulbs in Infocus projectors, differs from y, the mean lifetime of light bulbs in Proxima projectors? Perform a two-tailed test. Then complete the parts below. Carry your intermediate computations to three or more decimal places and round your answers as specified in the table. (If necessary, consult a list of formulas.) (a) State the null hypothesis H, and the alternative hypothesis H. = : H H 4 2 (b) Determine the type of test statistic to use. D-0 OSO Degrees of freedom: 14 (c) Find the value of the test statistic. (Round to three or more decimal places.) 0.403 |(d) Find the p-value. (Round to three or more decimal places.) 0.6929 (e) Can we conclude that u, the mean lifetime of light bulbs in Infocus projectors, differs from u, the mean lifetime of light bulbs in Proxima projectors?

The blue catfish (Ictalurus Furcatus) is the largest species of North Amercian catfish. The current world record stands at 143 pounds, which was caught in the John H. Kerr Reservoir (Bugg's Island Lake) located in Virginia. According to Amercian Expedition, the average weight of a blue catfish is between 20 to 40 pounds. Given that the largest blue catfish ever caught was at the John H. Kerr Reservoir, you believe that the mean weight of the fish in this reservoir is greater than 40 pounds. If you are going to test this claim, what would be your null and alternative hypotheses? Ho: HA: p> v Submit Question

Joan's Nursery specializes in custom-designed landscaping for residential areas. The estimated labor cost associated with a particular landscaping proposal is based on the number of plantings of trees, shrubs, and so on to be used for the project. For cost-estimating purposes, managers use two hours of labor time for the planting of a medium-sized tree. Actual times from a sample of 10 plantings during the past month follow (times in hours). B, C, and D

A recent study on driving behavior examined whether the combination of high driving skills and low safety skills is dangerous. Participants were classified as high or low in driving skill based on responses to a driver-skill inventory, then classified as high or low in safety skill based on responses to a driver-aggression scale. An overall measure of driving risk was obtained by combining several variables such as number of accidents, tickets, tendency to speed, etc. The following data were obtained. Use a 2 x 2 ANOVA with the .05 significance level to evaluate the results. What cutoff score(s) should be used? Driving Skill Low High Safety Skill Low M1=5 M2=4.5 S1=2.7 S2=3.8 N1=6 N2=6 HIgh M3=3 M4=3.5 S3=2.9 S4=2.5 N3=6 N4=6 Group of answer choices +4.35 +3.40 +3.49 +4.26

A County Board of Supervisors has appointed an urban planning committee to evaluate proposed community development projects. The committee is analyzing, among other things, data on household incomes in two cities within the county. They have collected data on the income of 77 households in each of the two cities. The histograms below show the distributions of the two sets of incomes (in thousands of dollars). Each histogram shows household income on the horizontal axis and number of households on the vertical axis. The means and standard deviations for the data sets are also given. City A City B 25+ 20+ 15+ 10+ 5- ← 10 20 30 40 50 60 70 80 90 100 City A mean: 73.96 thousand dollars City A standard deviation: 20.30 thousand dollars Explanation 25- 20- 15- 104 5+ 10 (a) Identify the data set for which it is appropriate to use the Empirical Rule. It is appropriate to use the Empirical Rule for the (Choose one) ▼ data set. 20 30 The committee wants to use the Empirical Rule to make some…

The dataset HollywoodMovies - 2e contains information on 970 movies that came out of Hollywood between 2007 and 2013. One of the variables is the budget (in millions of dollars) to make the movie. What would be the relevant parameter and statistic for this problem (think -- is this categorical or quantitative)? O u: The mean budget of all Hollywood Movies made between 2007 and 2013. O p: The average proportion of budgets of Hollywood Movies made between 2007 and 2013. T: The mean budget of all Hollywood Movies made between 2007 and 2013. Op: The proportion of Hollywood Movies made between 2007 and 2013.

The mean monthly food budget for 53 residents of the local apartment complex is $648 . What is the best point estimate for the mean monthly food budget for all residents of the local apartment complex?

The Coca-Cola Company reported that the mean per capita annual sales of its beverages in the United States was 423 eight-ounce servings (Coca-Cola Company website, February 3, 2009). Suppose you are curious whether the consumption of Coca-Cola beverages is higher in Atlanta, Georgia, the location of Coca-Cola's corporate headquarters. A sample of 36 individuals from the Atlanta area showed a sample mean annual consumption of 460.4 eight-ounce servings with a standard deviation of s=101.9. Answer questions 8-10.

A statistics content developer at Aplia wanted to know whether study skills are related to memory quality. She invited student volunteers to perform an online memory task. The students saw a list of 60 words and were then asked to recognize a list of 10 words that were on the original list. Students were also asked to provide their GPAs.   Consider the following data set, which was collected from student volunteers in 2009. The table gives the frequency for five intervals of scores on the number of correctly identified words. Use the dropdown menus to complete the table by filling in the missing values for the proportions and percentages. Score Interval f Proportion Percentage 9–10 29 0.19 19% 7–8 53           5–6 50           3–4 22 0.14 14% 1–2 1 0.01 1%

A doctor wanted to determine whether there is a relation between a male’s age and his HDL (so-called good cholesterol). He randomly selected 9 of his patients and determined their HDL cholesterol. The data is reported in the table below: c) Compute r and r2. Interpret these statistics. d) What is your opinion of the usefulness of using age as a predictor of HDL?