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One of the authors once spun his tennis racquet 100 times and found that it landed with the label up for 46 of those 100 spins (0.46). For testing whether the probability (that a spun tennis racquet... Write the null and alternative hypotheses for this new question. Suppose we didnt have a preconceived notion that the right front tire would be chosen more oft en, but just wanted to find out if it... Implement a test to compare the baseline heart rate initially (2000) and after 10 years of exercise (2010), and report a two-sided p-value? The subject also recorded his heart rate at baseline and 5... Provide a 95% CI for the difference in mean baseline heart rate between starting an exercise program (2000) and after 10 years of regular exercise (2010)? The subject also recorded his heart rate at... Assess the impact of the program statistically (use a two-sided test)? Dentistry In a study, 28 adults with mild periodontal disease are assessed before and 6 months after implementation of a... Carry out a non-parametric procedure for testing the hypothesis that lengths of stay are comparable in the two hospitals? Health Services Administration Suppose we want to compare the length of... The polling agency wishes to test whether there is evidence that more than 50% of likely voters will likely vote for the incumbent. a. State the null and alternative hypotheses for this test. b. What... How many participants need to be enrolled in each group to have a 90% chance of detecting a significant difference using a two-sided test with = .05 if compliance is perfect? Cardiovascular Disease... Perform the test in Problem 10.6, and report a p-value? Refer to Table 2.13 (p. 36). Table 2.13: Hospital-stay data To determine a 99% confidence interval using the interval of plausible values method, what significance level should be used on the two-sided tests? What proportion of people in each group developed abnormal triglyceride levels over the course of the study? Are these proportions measures of prevalence, incidence, or neither? Ophthalmology One... Test for the statistical significance of this regression line using the F test? Hematology The data in Table 11.17 are given for 9 patients with aplastic anemia [11]. Table 11.17: Hematologic data... What is the estimated standard error of the slope estimate? Hypertension The INTERSALT Study investigators collected standardized data on timed 24-hour urinary excretion for 10,079 men and women from... Provide a 95% Cl for the true slope ()? Hypertension The INTERSALT Study investigators collected standardized data on timed 24-hour urinary excretion for 10,079 men and women from 52 population... The regression coefficient for smoking is 0.7 ± 0.1, p < .001. Does this mean that smokers have higher pulmonary function than nonsmokers? Why or why not? Table 11.31: FEV.DOC Some descriptive... Which of the following is NOT true about quartiles? A. The lower quartile is always smaller than the upper quartile. B. Quartiles can be calculated by determining the median of the values above/below... Which of the following statements are true and which are false? a. In a paired design, each pair of observations always consists of measuring the same individual twice. b. In a paired design, each... What is the estimated OR for MI comparing men with severe vertex baldness vs. no baldness after controlling for age? Cardiovascular Disease A study was performed relating baldness pattern to MI... Which of the following is an example of a paired design? A. A teacher compares the pretest and posttest scores of a group of students. B. A teacher compares the scores of students using a computer... To test reaction times, a computer program will display a red circle. When it changes to yellow, the users click the mouse as fast as they can. The program will then display the reaction time.... Compare the incidence density of breast cancer in past users vs. never users, and report a p-value? Cancer The data relating oral-contraceptive (OC) use and the incidence of breast cancer in the age... A researcher takes a sample of sibling-pairs from two-child families. All individuals are given a test of their impatience, hypothesizing that older siblings tend to have higher levels of impatience.... Using the KruskalWallis test, determine whether there is enough evidence provided by the accompanying data to enable us to infer that at least two population locations differ. (Use α =... Statistics students conducted a test to see if people could taste the difference between Coke and Pepsi. They fill two cups with Coke and a third with Pepsi. They then asked their subjects which... Apply exponential smoothing with w = .1 to help detect the components of the following time series. Period 4 5 45 2 43 3 42 Time Series 46 38 3. 9. 10 Period Time Series 48 50 49 46 45 a. In a taste test of a new beer, 25 people rated the new beer and another 25 rated the leading brand on the market. The possible ratings were Poor, Fair, Good, Very Good, and Excellent. The... Describe the parameter of interest in words. (You can use the symbol to represent this parameter.) To help answer this question Pew Research(2009) conducted a survey of nationally representative 242... A law enforcement agency, administering breathalyzer tests to a sample of drivers stopped at a New Years Eve roadblock, measured the following blood alcohol levels for the 25 drivers who were... In testing the heat resistance of electrical components, safety engineers for an appliance manufacturer routinely subject wiring connectors to a temperature of 450 degrees Fahrenheit, then record the... The following data describe U.S. manufacturers shipments of general aviation jet aircraft from 1979 through 1998: a. Construct a graph of the time series. Does the overall trend appear to be upward... Given the four sample proportions 0.66, 0.45, 0.73, and 0.44, determine the MAD statistic. Create a scatterplot of the data with hand span on the x-axis and number of Tootsie Rolls on the y-axis. Is hand span a good predictor of how much candy you can grab? Using 45 college students as... The electric company is in the process of building a new power plant. There is some uncertainty regarding the size of the plant to be built. If the community that the plant will service attracts a... There is a garbage crisis in North Americatoo much garbage and no place to put it. As a consequence, the idea of recycling has become quite popular. A waste-management company in a large city is... Suppose that in Exercise 22.14 a consultant offers to analyze the problem and predict the amount of electricity required by the new community. To induce the electric company to hire her, the... A computer system uses passwords constructed from the 26 letters (az) or 10 integers (09). Suppose that 10,000 users of the system have unique passwords. A hacker randomly selects (with replacement)... Few of the shark attacks listed in Table 2.1 are fatal. Overall, 63 fatal shark attacks were recorded in the ISAF from 2004 to 2013, with 2 reported in Florida, 2 in Hawaii, 4 in California, 15 in... The news program wishes to test whether there is evidence that more than three-quarters of U.S. adults are opposed to the verdict. Five hundred and sixty two participants participated in the survey,... At the local cell phone store, the probability that a customer who walks in will purchase a new cell phone is 0.2. The probability that the customer will purchase a new cell phone protective case is... Most dermatologists recommend using sunscreens that have a sun protection factor (SPF) of at least 30. One of the authors wanted to find out whether the SPF of sunscreens used by students at her... Consider a manufacturing process that is producing hypodermic needles that will be used for blood donations. These needles need to have a diameter of 1.65 mmtoo big and they would hurt the donor... Suppose we are constructing a confidence interval using repeated tests of significance to develop an interval of plausible values. Using two-sided tests each time with the following null hypotheses,... Suppose I am conducting a test of significance where the null hypothesis is my cat Grayce will pick the correct cancer specimen 25% of the time and the alternative hypothesis is that she will pick... Number of degrees awarded by a college each year for the last 10 years Determine whether the data are qualitative or quantitative. Ages of children in a preschool. Classify each variable as discrete or continuous. Researchers Wilt et al. (New England Journal of Medicine, 2012) investigated whether surgery, compared to just observation, was (more) effective in improving mens survival chances aft er being... Construct a histogram, frequency polygon, and ogive for the data in Exercise 5. Data from 5 90 420 300 194 640 68 268 276 620 76 165 833 370 53 132 600 594 70 308 574 215 109 317 850 212 300 256 187 If a die is rolled one time, find these probabilities: a. Getting a number less than 7. b. Getting a number greater than or equal to 3 c. Getting a number greater than 2 and an even number d. Getting... You may have heard someone say that drinking coffee will stunt your growth. To test this, college students were asked their heights and if they were coffee drinkers. The data file CoffeeHeight.txt... Three bands and two comics are performing for a student talent show. How many different programs (in terms of order) can be arranged? How many if the comics must perform between bands? Six students are performing one song each in a jazz vocal recital. Two students have repertoires of five numbers, and the others have four songs each prepared. How many different programs are... Cards numbered 110 are shuffled and dealt face down. What is the probability that they are in order? In building new homes, a contractor finds that the probability of a home buyer selecting a two-car garage is 0.70 and of selecting a one-car garage is 0.20. Find the probability that the buyer will... Reconsider the previous exercises about the study of whether there is an association between number of Facebook friends and a persons sex. The following is output from carrying out the randomization... For each of the following, indicate whether or not a paired analysis would be appropriate. a. A school cafeteria offers a vegetarian and a nonvegetarian option for lunch every day. For a period of... Suppose an instructor wants to study the association between caffeine intake and performance in the long jump. Th e instructor asks her students to suggest ways to collect data to investigate this... Suppose you are testing the hypotheses H 0 : d = 0 and H a : d 0 in a paired-design test and obtain a p-value of 0.02. Also suppose you computed confidence intervals for d . Based on the p-value... Determine whether the distribution represents a probability distribution. If it does not, state why. P(X) 10 10 10 |-12 2. Student researchers wanted to see whether a short delay between seeing a list of words and when people were asked to recall them would hinder memorization. The subjects were shown a list of words to... Student researchers wanted to see if a persons reaction time is slower if they use their nondominant hand to click a computer mouse compared to using their dominant hand. The researchers had a... In a study of parents perceptions of their childrens size, researchers Kaufman et al. (Current Biology, 2013) asked parents to estimate their youngest childs height. The researchers hypothesized that... Refer to the previous exercise about the study of parents perceptions of their childrens size by researchers Kaufman et al. (Current Biology, 2013). Recall that the sample of 39 parents... In Exercise 15, find the expectation if a person buys two tickets. Assume that the players ticket is replaced after each draw and that the same ticket can win more than one prize. In exercise 15 A... A landscape contractor bids on jobs where he can make $3000 profit. The probabilities of getting 1, 2, 3, or 4 jobs per month are shown. Find the contractors expected profit per month. Number of jobs... Determine whether the distribution represents a probability distribution. If it does not, state why. 3 14 12 P(X) 13 13 13 13 13 A department store manager randomly sampled customers in her store. She recorded the number of minutes each customer spent in the store and then asked the customers how many miles they had traveled... A company purchases large lots of a certain kind of electronic device. A method is used that rejects a lot if 2 or more defective units are found in a random sample of 100 units. (a) What is the mean... The admissions committee at a college does not distinguish between different types of high school extracurricular activities. As far as it is concerned, being a member of the tiddlywinks club is... A persons knowledge of English grammar is measured by a 50-item multiple choice test. Each correct answer is worth 2 points, so scores can range from 0 to 100. English grammar knowledge is being... Use the rounding rules to round the following. 189.9895 = The distribution of prices of all the new cars sold in a year, including Ferraris, Lamborghinis, and other high-end cars, is probably: a. Normally distributed. b. Positively skewed. c. Negatively... For a row in the middle of a frequency distribution, either ungrouped or grouped, which statement is probably true? a. f > f c b. f c > f c. f = f c d. None of these statements is ever true. Reconsider the previous question on how different generations view marriage. The results are shown in the table in the previous exercise and can also be found in the file MarriageViews. a. Identify... Refer to the previous exercise about the study of different HIV intervention programs. Suppose that the observed cell counts were actually twice as big as those reported in the original study. For... Calculate s for these data, which have a mean of 3.30: 1.4, 2.2, 4.5, 4.1, and 4.3. Are the validity conditions met to complete a theory-based t-test on these data? Explain. Whether the conditions are met or not, use a theory-based t-test to find a p-value. How does this p-value... What percentage of cases in a normal distribution fall from the mean to a z score of 2.58? A regression table is shown based on data used to test an association between the amount of sleep someone had the previous night (in hours) and the time needed to complete a paper and pencil maze (in... Within 2 standard deviations of the mean in a normal distribution, about ____% of the cases fall. If two outcomes are ____, then only one outcome can occur at a time. ____ concerns how likely an outcome is to occur. A researcher wants to investigate whether there is a relationship between annual company profit ($) and median annual salary paid by the company ($). The researcher collects data on a random sample... In the population of children in a school district, the mean number of days tardy per year is 2.8. A sociologist obtained a sample of children from single-parent families and found the mean number of... If the 95% confidence interval for the difference between population means falls close to zero, this means the size of the effect may be ____. A beacon transmits a signal every 10 minutes (such as 8:20, 8:30, etc.). The time at which a receiver is tuned to detect the beacon is a continuous uniform distribution from 8:00 a.m. to 9:00 a.m.... Consider the well failure data given below. Let A denote the event that the geological formation has more than 1000 wells, and let B denote the event that a well failed. Are these events independent?... Numerators in variance formulas are ____. The critical value of F depends on the degrees of freedom for the ____ and the degrees of freedom for the ____ of the F value. Between-subjects, one-way ANOVA assumes that the dependent variable in each population is ____ distributed. Between-subjects, one-way ANOVA is used when there is one ____ and ____ groups. Between-group variability, the numerator in an F ratio, is made up of ____ and ____. ____ effect is the term used to label the effect of the independent variable. Variability within a set of scores is called ____ variability. The quality control department of a fabric finishing plant is studying the effects of several factors on dyeing for a blended cotton/synthetic cloth used to manufacture shirts. Three operators, three... An engineer is interested in the effect of cutting speed (A), metal hardness (B), and cutting angle (C) on the life of a cutting tool. Two levels of each factor are chosen, and two replicates of a 2... Some post-hoc tests have a greater likelihood of making a ____ error and others a greater chance of a ____ error. The higher the percentage of variability in the dependent variable explained by the independent variable, the ____ is the size of the effect. One determines if an F ratio is statistically significant by comparing F to ____. An F ratio in between-subjects, one-way ANOVA is calculated as the ratio of MS____ to MS____. If q = 4.05, MS Within = 6.87, and n = 11, what is HSD?
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