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
Dafna1 [17]
3 years ago
11

A researcher compares the effectiveness of two different instructional methods for teaching electronics. A sample of 138 student

s using Method 1 produces a testing average of 61. A sample of 156 students using Method 2 produces a testing average of 64.6. Assume the standard deviation is known to be 18.53 for Method 1 and 13.43 for Method 2. Determine the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2. Step 1 of 2: Find the critical value that should be used in constructing the confidence interval.
Mathematics
1 answer:
yan [13]3 years ago
5 0

Answer:

The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).

Step-by-step explanation:

The (1 - <em>α</em>)% confidence interval for the difference between population means is:

CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}

The information provided is as follows:

n_{1}= 138\\n_{2}=156\\\bar x_{1}=61\\\bar x_{2}=64.6\\\sigma_{1}=18.53\\\sigma_{2}=13.43

The critical value of <em>z</em> for 98% confidence level is,

z_{\alpha/2}=z_{0.02/2}=2.326

Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:

CI=(\bar x_{1}-\bar x_{2})\pm z_{\alpha/2}\times \sqrt{\frac{\sigma^{2}_{1}}{n_{1}}+\frac{\sigma^{2}_{2}}{n_{2}}}

     =(61-64.6)\pm 2.326\times\sqrt{\frac{(18.53)^{2}}{138}+\frac{(13.43)^{2}}{156}}\\\\=-3.6\pm 4.4404\\\\=(-8.0404, 0.8404)\\\\\approx (-8.04, 0.84)

Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).

You might be interested in
HELP ASAP <br><br> Find the zeros of y = x^2 - 4x - 9 by completing the square.
Alla [95]

Answer: x= 2 + √ 13 ,2- √ 13

Step-by-step explanation:

Replace y with 0 and solve for x

4 0
3 years ago
Read 2 more answers
Chris completed 20% of a 50 page reading assignment. How many pages did he read?
MrRissso [65]

Answer:

10 pages

Step-by-step explanation:

To find 20% of 50, multiply .20 x 50

.2 × 50 = 10

8 0
2 years ago
Read 2 more answers
Find the difference of -3/5 - (-5/9)<br> 20 points y'all<br><br> thanks<br> -Throckmorton
AlladinOne [14]
The work to your question

6 0
3 years ago
A 9-kilogram bag of sugar cost $27.54. what is the unit price ?
shusha [124]

Answer:

$3.06

Step-by-step explanation:

1 kg = $27.54

27.54/9 kilogram

4 0
3 years ago
Is it B, am I right, please answer fast.
yKpoI14uk [10]

Answer: C

Step-by-step explanation:

I’m pretty sure it’s c because x isn’t less than -2. It goes forever in the directions of positive and negative infinity

8 0
3 years ago
Read 2 more answers
Other questions:
  • Product of nine and the sum of a number Z and four
    12·2 answers
  • Write a recursive formula to represent the total height of the nth stair above the ground if the height of each stair is 18 cm.
    12·1 answer
  • How do you find the slope of a table​
    13·1 answer
  • Find the length of the darkened arc. Leave your answer in terms of pi.​
    13·1 answer
  • HELP ME PLZ PLZ PLZ!HELP ME PLZ PLZ PLZ!
    7·1 answer
  • Help pls I’ll give extra points
    6·1 answer
  • I can't figure out the answer
    10·2 answers
  • <img src="https://tex.z-dn.net/?f=%5Cfrac%7B350m%7D%7B1s%7D" id="TexFormula1" title="\frac{350m}{1s}" alt="\frac{350m}{1s}" alig
    10·1 answer
  • Find the value of x.​
    8·1 answer
  • For the equation 2x - y = 1, if x = 0, then y = ?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!