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
GarryVolchara [31]
3 years ago
6

Each year, all final year students take a mathematics exam. It is hypothesised that the population mean score for this test is 8

0. It is known that the population standard deviation of test scores is 13. A random sample of 23 students take the exam. The mean score for this group is 71. a)Calculate the 90% confidence interval for the population mean test score. Give your answers to 2 decimal places.
Mathematics
1 answer:
VMariaS [17]3 years ago
7 0

Answer:

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.

Step-by-step explanation:

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\alpha = \frac{1 - 0.9}{2} = 0.05

Now, we have to find z in the Ztable as such z has a pvalue of 1 - \alpha.

That is z with a pvalue of 1 - 0.05 = 0.95, so Z = 1.645.

Now, find the margin of error M as such

M = z\frac{\sigma}{\sqrt{n}}

In which \sigma is the standard deviation of the population and n is the size of the sample.

M = 1.645\frac{13}{\sqrt{23}} = 4.46

The lower end of the interval is the sample mean subtracted by M. So it is 71 - 4.46 = 66.54

The upper end of the interval is the sample mean added to M. So it is 71 + 4.46 = 75.46

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.

You might be interested in
How would you solve these if the X goes; -3,-2,-1,0,1,2,3 in a table format
Vlada [557]
Hello,

solution is jointed

7 0
3 years ago
Please help me i really need help please
jeka94
V= 735.62

volume formula for sphere is v= 4/3 π r3
the radius is half of the diameter so v= 4/3 π 5.6 3

i think?
8 0
2 years ago
Part A<br> What are the possible outcomes of rolling a six-sided die?
nikdorinn [45]

Answer:

the possible outcomes are :

  • one (1)
  • two (2)
  • three (3)
  • four (4)
  • five (5)
  • six (6)
4 0
2 years ago
A group of 8 friends each buy 1 ticket and 1 small popcorn at the movie
ivolga24 [154]

Answer:

1 Small popcorn cost $2.95

Step-by-step explanation:

7.50 * 8 = 60

83.60 - 60 = $23.60

23.60 / 8 = $2.95

6 0
2 years ago
Identify the equation that describes the line in slope-intercept form.
slega [8]

Answer y-2x+5 or it will be y=-2x+11

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
Other questions:
  • Given: -2x &lt; 10. Choose the solution set.
    8·1 answer
  • Find the axis of symmetry for the function below.<br> 2x^2 – 8x + 5 = 0
    12·1 answer
  • What is an equivalent expression (m ^1/3)^ 1/5<br><br> *the fractions are powers btw*
    10·1 answer
  • 15 points...........
    9·2 answers
  • Determine the slope of the linear function.
    12·2 answers
  • Let event Aequalssubject is telling the truth and event Bequalspolygraph test indicates that the subject is lying. Use your own
    15·1 answer
  • Math problem I need help giving brainlist
    6·2 answers
  • WILL GIVE BRAINLIEST IF DO QUICKLY!!!!!: Let f(x) = 2/x and g(x) = x − 3. Write an expression for f(g(x))
    10·1 answer
  • Solve 7(3-y)=5(y+5).​
    11·2 answers
  • Find the value of 2a -t<br> for a = 7 and t = 10.
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!