An engineer wishes to determine the width of a particular electronic component. If she knows that the standard deviation is 3.6 mm, how many of these components should she consider to be 90% sure of knowing the mean will be within ±0.4 mm?

Identify the symbols used for each of the following: (a) sample standard deviation; (b) population standard deviation; (c) sample variance; (d) population variance. If sample data consist of weights measured in grams, what units are used for these statistics and parameter a. The symbol for sample standard deviation is b. The symbol for population standard deviation is c. The symbol for sample variance is d. The symbol for population variance is If sample data consist of weights measured in grams, then correctly complete the following sentences. a. The unit for sample standard deviation would be b. The unit for population standard deviation would be C. The unit for sample variance would be ▼ d. The unit for population variance would be ▼ C

For questions 6 through 11, refer to the following table, representing responses from the 2018 GSS: Respondent Sex Mean Hours Worked Last Week Standard Deviation N Male 44.60 14.969 670 Female 38.15 13.276 711 6. What proportion of females worked less than 40 hours per week?    a. How many people in the sample does that correspond to?7. What percentage of males worked between 40 and 50 hours per week?    a. How many people in the sample does that correspond to?8. What number of hours worked among females corresponds with a Z score of -2.00?9. Calculate the number of hours worked last week that corresponds to the 95th percentile for each sex.    a. If you were going to calculate the 75th percentile, what Z value would you use? 10. Calculate the standard error for both males and females.    a. What are you using for sigma, and why? 11. Calculate the 95% confidence interval for each sex. Can you say with 95% confidence that they are different? Why or why not?    a. If you were…

To compare the dry braking distances from 30 to 0 miles per hour for two makes of automobiles, a safety engineer conducts braking tests for 35 models of Make A and 35 models of Make B. The mean braking distance for Make A is 42 feet. Assume the population standard deviation is 4.7 feet. The mean braking distance for Make B is 45 feet. Assume the population standard deviation is 4.4 feet. At a = 0.10, can the engineer support the claim that the mean braking distances are different for the two makes of automobiles? Assume the samples are random and independent, and the populations are normally distributed. Complete parts (a) rari rz (b) Find the critical value(s) and identify the rejection region(s). The critical value(s) is/are (Round to three decimal places as needed. Use a comma to separate answers as needed.)

Solve only the part a, b and c for question 10.

An engineer wishes to determine the width of a particular electronic component. If she knows that the standard deviation is 3.8 mm, how many of these components should she consider to be 80% sure of knowing the mean will be within ±0.2±0.2 mm? 8562 38 256 25 593

The temperature reading from a thermocouple placed in a constant-temperature medium is normally distributed with mean u, the actual temperature of the medium, and standard deviation o. n USE SALT What would the value of o have to be to ensure that 95% of all readings are within 0.8° of µ? (Round your answer to four decimal places.) You may need to use the appropriate table in the Appendix of Tables to answer this question.

What is the population standard deviation using the following formula

I need help solving this problem.

A section of highway is posted with a 55 mph speed limit. In fact, speeds of cars traveling on this section are normally distributed with mean 58 mph and standard deviation 5 mph. If the state patrol decides to ticket cars in the fastest 10 %, at what speed will they start ticketing ? Round your answer to the first decimal position.