1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
xz_007 [3.2K]
3 years ago
7

A professor records the difference between the marks scored by the students in the class test last week and those scored in the

present week. The mean difference for 35 students was 12 with a standard deviation of 3. Construct a 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students.
Mathematics
1 answer:
dezoksy [38]3 years ago
4 0

Answer: (10.82\ , 13.18)

Step-by-step explanation:

The confidence interval for population mean is given by :-

\mu\pm\ z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}

Given : Sample size : n= 35  , large sample (n>30)

Mean difference : \overline{x}=12

Standard deviation : \sigma=3

Significance level : \alpha=- 1-0.999=0.001

Critical value : z_{\alpha/2}=z_{0.0005}=3.4807567

Now, the 99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students will be :-

12\pm\ (3.4807567)\dfrac{2}{\sqrt{35}}\\\\=12\pm1.18\\\\=(10.82\ , 13.18)

Hence, the  99.9% confidence interval for the mean difference between the marks scored last week and marks scored this week by all the students = (10.82\ , 13.18)

You might be interested in
What is the total amount for an investment of $1,250 invested at 9.6% for 12 years and compounded continuously?
lianna [129]
Answer A hope that help
8 0
3 years ago
A wise man once said, “500 reduced by 4 times my age is 256.” What is his age
ch4aika [34]
The answer to this question is 2.048
5 0
3 years ago
Read 2 more answers
Need help with perfect square! 40 points
andriy [413]
The value of C would be 25
6 0
3 years ago
Read 2 more answers
PLEASE HELP LATS MATH PROBLEM <br> A, B and C
Llana [10]

Answer:

a) Set up triangles where the hypotenuse is 16ft (the ladder) and one of the two edges are 1, 2, 3, 4, 5ft (the base of the ladder).  Use a^2 + b^2 = c^2 where a is the base length, c is the hypotenuse and b is the value you are trying to find.

Ex w/ 1ft base:

1^2 + b^2 = 16^2

1 + b^2 = 256

b^2 = 255

b = 15.97ft.

b) Simply take your answers from part a) and add 5.5ft (the height of the girl) to them.

Ex w/ 1ft base:

15.97ft + 5.5ft = 21.47ft

c) Using logic here think about it.  Let's take the 1ft base as the example.  Marissa standing on top of the ladder is 21.47ft.  That's clearly not high enough to reach the cat . . . but what happens if Marissa reaches upwards.  As long as her arms can reach roughly 1.53ft above her head she should be able to reach it.

Step-by-step explanation:

lolz

8 0
3 years ago
The movie rental store CineStar offers customers two choices. Customers
nikdorinn [45]

Answer:

The yearly fee + $2 per movie

Step-by-step explanation:

Because lets say you rent 50 movies per year. Well with the yearly fee its $145. But with no yearly fee and just $3.50 per movie it’s $175.

3 0
3 years ago
Other questions:
  • -3=z-8 Solve and answer the equation
    10·1 answer
  • To add or subtract values written in scientific notation, the numbers must have the same______of 10
    15·1 answer
  • In 2000, 900 students played soccer. In 2001, 180 additional students played. How many students must play soccer in 2002 for the
    14·1 answer
  • Name:
    10·1 answer
  • Can anyone help me please
    7·1 answer
  • A construction crew is building a swimming pool that is 6 feet wide, 20 feet long, and 8 feet deep. Once everything is complete,
    7·1 answer
  • What is the geometric mean of 3 and 6
    14·2 answers
  • Help please the question is on the image
    15·1 answer
  • Clare earns 75 the next week from an after school job and deposits just enough into her account so that she is out of debt.
    15·1 answer
  • Over a 5-hour period, the
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!