For Exercises 5–8: (a) State the null hypothesis and the alternate hypothesis. (b) State the decision rule. (c) Compute the value of the test statistic. (d) What is your decision regarding H0? (e) What is the p-value? Interpret it.
5. The manufacturer of the X-15 steel-belted radial truck tire claims that the mean mileage the tire can be driven before the tread wears out is 60,000 miles. Assume the mileage wear follows the
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Loose Leaf for Statistical Techniques in Business and Economics
- A study done in 1997 showed that 4.7% of mothers smoked cigarettes during their pregnancy. An obstetrician feels that this percentage is higher now. To test this, the obstetrician takes a sample of 150 mothers and finds that 9 of them smoked during their pregnancy. Test the obstetrician's claim at the a=0.05 level of significance. Write your answer in the following form P-Value, Conclusion Example: 0.15, There is not sufficient evidence that the mean weight of pandas is less than 200 pounds. Edit View Insert Format Tools Table 12pt Paragraph v BIU Av2v T2く v E v Pv ...arrow_forwardSpending on concessions at the movies varies by age of the movie goer. A random sample of 100 adults in their 40's found that 70 purchased popcorn. A random sample of 100 adults less than 40 years old found that 59 purchased popcorn. a. State the hypotheses for determining there is a difference in the proportion of adults who purchase popcorn in each age group. b. Calculate the test statistic. c. Calculate the p-value. d. Interpret the p-value. e. State your conclusion. f. Would a confidence interval for the difference in proportions contain zero? Explain without constructing the interval.arrow_forwardInvestigators are trying to determine if the contamination of a town well led to significant increases in adverse health effects. During the period of time when water was consumed from this contaminated well, there were 16 birth defects among 414 births. After this well was shut off, there were 3 birth defects among 228 births. You asked to determine if the rate of birth defects was higher when the contaminated well was in use. a. Test the claim that the contaminated well was not associated with a change in the rate of birth defects in the community at the alpha = 0.05 level, by using the two-proportion z test. Confirm your answers using Stata. b. Calculate a 95% confidence interval for the true difference between the proportions of birth defects when the contaminated well was in use versus when the well was shut down. c. Construct the 2x2 contingency table representing the data to Calculate the odds of a birth defect when the contaminated water was consumed and when the well was shut…arrow_forward
- Short Answer and SPSS K1. Oodles of Noodles, an artisanal noodle manufacturing company in Brooklyn, makes three kinds of handmade, organic, ethically sourced noodles; Thick, Medium and Thin. They are interested in determining which noodle people tend to prefer and which one has the best "mouth feel" as it is referred to in the food industry. They consult with you (as a statistical expert) to collect data from their consumers. You devise a pleasantness rating scale for the noodles with 1 being the most pleasant to 5 being the least pleasant (so that lower scores indicate better "mouth feel"). You randomly assign 60 individuals to one of three separate groups. Twenty individuals taste and rate the thick noodles, another twenty individuals rate the medium noodles, and another twenty individuals rate the thin noodles. The data for this question can be found in the file labeled "Noodles" on BB. (20 points) (FYI, I like thinner noodles, think Ramen or angel hair pasta, what about you?) Using…arrow_forwardYou take a survey that is supposed to measure whether you are an extrovert or not. The score you get on the extrovert survey is a z-score of 2.0. What does that mean about your level of extraversion compared to the average score?arrow_forwardYou are a consumer psychologist interested in holiday spending. A national census reports that the American family spent an average of µ = $81 for Halloween candy and costumes last year. A sample of N = 16 families this year produced a mean of $85 with s = 20. t-value ? t-critical?arrow_forward
- woman loves, as everyone should, to collect and analyze statistical information. He wishes to find a relationship between how many hours students study and how they do on their statistics tests. He takes a random sample of 16 students at Ideal U., asks how many hours they studied for a university-wide stat testand how they did on the test, enters the data into a computer for analysis and presents the results below. ANALYSIS OF HOURS AND GRADES (n = 16): Descriptive Statistics: HOURS GRADES Mean: 4.2 75.8 Mode: 5.0 79.0 St. Dev: 2.3 10.1 Quartiles: Q0 2.0 34.0 Q1 3.2 53.7 Q2 4.7 78.5 Q3 6.3 86.9 Q4 9.0 97.0 Regression Analysis: Reg. Eq. is: GRADE = 16.9 + 9.025*HOURS Rsquared = .985 std error = 0.027 F = 8.52 p = .018 What is the correlation between hours studied and grades? a. 0.016 b. 0.992 c. 0.985 d. cannot be determined e. 0.12arrow_forwardQ.1 Dr. Star is interested in whether the physical coordination skills among low-income pre-school children are different from those of other children. She knows the population mean for the Pre- School Coordination Activity Test (PCAT) is 120 with o x= 10. She tests 80 preschoolers from low-income families and obtains an X= 122. a. Should Dr. Star do a one-tailed or a two-tailed test? Explain your answer. b. State the appropriate H o and H a , given your answer in part a. c. Use at a = 0.05. What is the value of zcrit ? d. Calculate z obt e. Using symbols, report your findings. f. What should Dr. Star conclude?arrow_forwardAn education researcher claims that 59% of college students work year-round. In a random sample of 300 college students, 177 say they work year-round. At a = 0.01, is there enough evidence to reject the researcher's claim? Complete parts (a) through (e) below. (a) Identify the claim and state H, and Ha. Identify the claim in this scenario. Select the correct choice below and fill in the answer box to complete your choice. (Type an integer or a decimal. Do not round.) O A. The percentage of college students who work year-round is not %. О В. % of college students work year-round. O C. At least % of college students work year-round. O D. At most % of college students work year-round. Let p be the population proportion of successes, where a success is a college student who works year-round. State Ho and Ha. Select the correct choice below and fill in the answer boxes to complete your choice. (Round to two decimal places as needed.) O A. Ho: ps Ha: p> O B. Ho: p2 O C. Ho: p O F. Ho: P= Ha:…arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillHolt Mcdougal Larson Pre-algebra: Student Edition...AlgebraISBN:9780547587776Author:HOLT MCDOUGALPublisher:HOLT MCDOUGAL