![leta18](/avatars/44981.jpg)
leta18
18.07.2020 •
Mathematics
The number of hours per day that Americans spend on social networking is approximately normally distributed. A random sample of 20 Americans who use social networks had
Solved
Show answers
More tips
- C Computers and Internet Dropbox: What is it and How to Use it...
- H Health and Medicine How to Increase Hemoglobin in the Blood...
- A Animals and plants How to Store Carrots: Tips for Homeowners...
- L Legal consultation Juvenile Justice: Who Needs It?...
- F Family and Home How to Choose the Best Diapers for Your Baby?...
- F Family and Home Parquet or laminate, which is better?...
- L Leisure and Entertainment How to Properly Wind Fishing Line onto a Reel?...
- L Leisure and Entertainment How to Make a Paper Boat in Simple Steps...
- T Travel and tourism Maldives Adventures: What is the Best Season to Visit the Luxurious Beaches?...
- H Health and Medicine Kinesiology: What is it and How Does it Work?...
Answers on questions: Mathematics
- M Mathematics write the number 100 as a product of it s prime factor in the same way write the factors in order from smallest to largest...
- M Mathematics I will give brainiest to whoever answers correctly !!...
- M Mathematics Explain why the expressions 8x(6-4) and 8x6-4 do not have the same value even though they look very similar? HELP!! PLEASE EXPLAIN IT IN 2 complete sentences. (ITS ALGEBRA)...
- M Mathematics You spent 9.5 hours playing Among Us this week. This is 2.75 hours more than the number of hours h you played last week. Which equation can be used to find h?...
- M Mathematics Just as you are recovering, your child falls ill. You know there have been mistakes in your medication dosages, so you hurriedly scan the Internet to make sure that what the doctor...
- M Mathematics what is the slope of the line 9x+5y=-25 1. -9 2. 5 3. 9/5 4. -9/5...
- M Mathematics Help- my tiny brain can’t figure this out...
- M Mathematics I will give brainiest to whoever answers correctly !!...
- M Mathematics A clothing business finds there is a linear relationship between the number of shirts, n, it can sell and the price,p, it can charge per shirt. In particular, historical data shows...
- M Mathematics Simplify completely the quantity x squared plus x minus 12 over quantity x squared minus x minus 20 divided by the quantity 3 x squared minus 24 x . (2 points) Select one: a. quantity...
Ответ:
B. (2.869, 3.411)
Step-by-step explanation:
The question is incomplete:
The number of hours per day that Americans spend on social networking is approximately normally distributed. A random sample of 20 Americans who use social networks had M = 3.14 hours and s = 0.58 hours. Find a 95% confidence interval for the actual mean number of hours that Americans spend on social networking.
A. (2.860, 3.420)
B. (2.869, 3.411)
C. (2.886, 3.394)
D. Not appropriate
We have to calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=3.14.
The sample size is N=20.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
The degrees of freedom for this sample size are:
The t-value for a 95% confidence interval and 19 degrees of freedom is t=2.093.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:
The 95% confidence interval for the mean is (2.869, 3.411).
Ответ: