limelight11
07.03.2020 •
Mathematics
The Police Department is investigating the need for a speed camera to be implemented on Swift Road. A sample of 60 cars passing through that road on a particular day were randomly selected and their speeds recorded. The speed limit on Swift Road is 60 miles per hour (mph). The mean speed for the sample was calculated as 41 mph. The standard deviation of the speeds for the sample was calculated as 3 mph. The standard deviation for the population of cars driving on Swift Road is unknown.
a)Select all the techniques that are commonly used to construct a confidence interval for the mean when the population standard deviation (?) is unknown:
Approximate the population standard deviation (?) with the sample standard deviation (s)
Replace the sample size (n) with n-1
Approximate the standard normal distribution with the Student's t distribution
Decrease the confidence level to compensate for the increased margin of error
b)Calculate the upper and lower bounds of the 90% confidence interval for the mean speed traveled on Swift Road. You may find this Student's t distribution tableuseful. Give your answers in mph to 2 decimal places.
Upper bound = mph
Lower bound = mph
Solved
Show answers
More tips
- F Food and Cooking Fresh and Easy Lemonade in 10 Minutes...
- S Sport How to wrap boxing hand wraps? Everything you need to know!...
- F Family and Home How to Sew Curtain Tapes: Best Tips from Professionals...
- A Animals and plants How to Grow Lime from a Seed: Simple Tips and Interesting Facts...
- C Computers and Internet How to Create a Folder on Your iPhone?...
- G Goods and services How to sew a ribbon: Tips for beginners...
- F Food and Cooking How to Make Mayonnaise at Home? Secrets of Homemade Mayonnaise...
- C Computers and Internet Which Phone is Best for Internet Surfing?...
- F Food and Cooking Everything You Need to Know About Pasta...
- C Computers and Internet How to Choose a Monitor?...
Answers on questions: Mathematics
- M Mathematics Alarge crane used at a construction site has a 253 foot reel of cable. a 3-foot section of cable weighs 2 pounds. what is the weight of the cable on the reel? write...
- M Mathematics Cindy’s puppy, zoey, has a basket of toys. there are 3 balls in the basket. there are 2 times as many stuffed animals as balls in the basket. there is 1 fewer bone...
- M Mathematics Ahigh school drama club is putting on their annual theater production there is a maximum of 800 tickets for the show the cost of the tickets are six dollars before...
- M Mathematics Howdy! id love to have these questions answered asap! you for the ! 1) which angle is not coterminal to 120 degrees? a. 840 b. -180 c. 480 2) use the unit circle and...
- M Mathematics Acomputer company has a special going in which all customers receive a free monitor and scanner with the purchase of a new computer. it costs the company $393.29 to...
- M Mathematics If the date of the second thursday of the month is a perfect square, what is the date of the last monday of the month?...
- M Mathematics Andre rents a bike for a day. the rental changes can be determined by the equation: r = $0.5d, where r is rental changes and d is number of days she rents the bike....
- M Mathematics If m arc cd = 143°, and m arc ab = 39°, what is m∠ dec ?...
- M Mathematics The ratio that relates how much debt a company has in proportion to its equity is?...
- M Mathematics 30.36 is what percent of 138...
Ответ:
Step-by-step explanation:
(a) Approximate the population standard deviation (?) with the sample standard deviation (s)
Approximate the standard normal distribution with the Student's t distribution
(b) The degree of freedom =n-1=60-1=59
Given a=0.1, t(0.05, df=59) =1.67 (from student t table)
So the lower bound is
xbar -t*s/vn =41 -1.67*3/sqrt(60) =40.35
So the upper bound is
xbar +t*s/vn =41 +1.67*3/sqrt(60) =41.65
Ответ: