![monkeys450](/avatars/44581.jpg)
monkeys450
28.11.2019 •
Mathematics
An srs of 380 high school seniors gained an average of ¯ x = 20.99 points in their second attempt at the sat mathematics exam. assume that the change in score has a normal distribution with standard deviation σ = 47.53 . we want to estimate the mean change in score μ in the population of all high school seniors.
(a) using the 68 – 95 – 99.7 rule or the z - table (table a), give a 95 % confidence interval ( a , b ) for μ based on this sample. (enter your answers rounded to three decimal places. if you are using crunchit, adjust the default precision under preferences as necessary. see the instructional video on how to adjust precision settings.)
Solved
Show answers
More tips
- F Food and Cooking Discovering the Benefits of Kiwi: From Its Nutritious Properties to Its Unusual Benefits...
- S Style and Beauty Discover the Art of Nail Design: How Do You Paint Your Nails?...
- P Philosophy How to Develop Extrasensory Abilities?...
- O Other Everything You Need to Know About Kudyabliks...
- C Computers and Internet The Twitter Phenomenon: What it is and How to Use it...
- C Computers and Internet How to Choose a Laptop: Expert Guide and Tips...
- C Computers and Internet How to Choose a Monitor?...
- H Horoscopes, Magic, Divination Where Did Tarot Cards Come From?...
- S Style and Beauty How to Make Your Lips Fuller? Ideas and Tips for Beautiful Lips...
- C Computers and Internet How to Learn to Type Fast?...
Answers on questions: Mathematics
- M Mathematics 7 9 10 11 Skylar travels 50 meters N and then goes 30 meters West before coming straight back south 20 meters. What distance did she travel? 12...
- M Mathematics 2 po 1. There are 25 computers in the classroom. There are 6 textbooks for every 2 computers. How many textbooks are there?...
- M Mathematics 726g 8305gSide A has a mass of 8305g while side B has a mass of 726g. How much mass mustShantel add to side B from side A so that the scale will be balanced?...
- M Mathematics Factor this trinomial fast please!x2 - 11x + 30...
- M Mathematics Please help me figure this out...
- M Mathematics Erica purchased adult and youth tickets for a movie. She bought x adult tickets for $7 each and y youth tickets for $5. Write an expression that can be used to show...
- M Mathematics 4x-6/3=5x-14/7 how many so...
- M Mathematics Help possssssssssssssssss...
- M Mathematics 5d divided by c+2;let d=10,c=5...
- M Mathematics What is the value of k...
Ответ:
Step-by-step explanation:
Hello!
Your study variable is X: scores obtained on mathematics SAT at the 2nd attempt of a high schooler.
This variable has a normal distribution and the population standard deviation is known σ= 47.53
Since you want to estimate the population mean, you have to work using the sample mean, its distribution is X[bar]~N(μ;σ²/n)
a.
Using the Z-table
[X[bar] ±
*(σ/√n)]
Where:
Z_{1-\alpha /2} = Z_{0.975} = 1.96
X[bar]= 20.99
n=380
[20.99 ±1.96*(47.53/√380)]
[16.2110;25.7689]
Using the 68-95-99.7 rule, since is based on the sample, the sample mean is x[bar] and the standard deviation for the sample mean distribution is: (σ/√n)
95% is between μ ± 2σ
Under the sample mean distribution:
mean: x[bar]= 20.99
standerd deviation: σ/√n = 47.53/√380
95% is between 20.99 ± 2*(47.53/√380) = 20.99 ± 2*2.4382
[16.1136;25.8664]
I hope it helps!
Ответ:
http://www.saylor.org/site/wp-content/uploads/2013/09/K12MATH007-Area-and-Perimeter-of-Triangles.pdf