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Unit 1 Review Worksheet Name:___________________________________________ 1. A marketing firm claims that its ad campaign will increase sales for a fast-food chain by 9%. In a random sample of 35 stores, the average increase in sales was 8% with a standard deviation of 4%. Find the z-value, rounded to the nearest hundredth. Is there enough evidence to reject the marketing firm’s claim? x= = = n= _________________________________________________________________________________________________ 2. a. State the null hypothesis: _________________________________________________________________________________________________ b. Compare the results of the two groups. Does the company have enough evidence to reject the null hypothesis? How do you know? 3. Find the standard deviation and variance for the vertical leap data without the insert. _______________________________________________________________________________________________ 4. The neighborhood association wants to know whether they should resurface the jogging trail at the local park. They survey the opinion of every household on 3 of the 10 blocks in the neighborhood. What kind of sample is this? ________________ 5. Scores on a test are normally distributed with a mean of 82 and a standard deviation of 6. Determine the probability that a randomly selected student scored more than 85. _________________________________________________________________________________________________ Unit 1 Review Worksheet Name:___________________________________________ 6. According to a survey of a random sample of households, 62% of the neighborhood prefers not to add a bench to the park. The survey’s margin of error is 8%. a. Determine whether the survey shows the majority’s preference. _________________________________________________________________________________________________ b. Determine the number of people who were surveyed. _________________________________________________________________________________________________ 7. The weights, in grams, of a sample of walnuts are shown. Calculate the mean absolute deviation/mean deviation. 8. 9. Determine the percent of the shaded region for each normal distribution curve: 10. 11. _________________________________________________________________________________________________ Unit 1 Review Worksheet 12. Name:___________________________________________ 13. 14. A speed reading course claims that it can boost reading speeds to 1050 words per minute. In a random sample of 49 people who took the course, the average was 1020 words per minute with a standard deviation of 90 words per minute. What is the z-value rounded to the nearest hundredth? F. The z-value is – 2.33. There is enough evidence to reject the claim. G. The z-value is -16.33. There is enough evidence to reject the claim. H. The z-value is – 1.96. There is not enough evidence to reject the claim. J. The z-value is – 2.33. There is not enough evidence to reject the claim. 15. A store owner wants to know if he sells more water or sports drinks. He records the number of sales for both products. What is the data-gathering technique used? A experiment B randomized survey C observational survey D voluntary survey 16. In a random sample of phone calls to a police station, 11 of the 25 calls were for emergencies. Suppose the police station receives 175 calls in one day. Predict the number of calls that will be for emergencies. _________________________________________________________________________________________________ 17. A cable network wants to know if viewers would rather watch a new show or the existing show. Out of a focus group of 600 randomly selected viewers, 300 watch the new show and 300 watch the old one. The company then has each group rate the shows. State the treatment, the treatment group, and the control group. treatment:____________________________________________________________________________________ treatment group:_____________________________________________________________________________ control group:________________________________________________________________________________ Unit 1 Review Worksheet Name:___________________________________________ 18. Arturo is offered two jobs. At Company A, the base pay is $42,000, and there is a 60% chance of getting a $4,000 bonus. At Company B, the base pay is $38,000, and there is a 25% chance of getting a $25,000 bonus. Compare the expected total for each job. 19. The probability distribution of the egg production of a farmer’s chickens is given below. What is the expected egg production for any one chicken? Egg Production n eggs 3 4 5 Probability of n eggs 0.25 0.7 0.05 20. Describe how the outlier affects the mean and standard deviation: 73, 75, 76, 37 _________________________________________________________________________________________________