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
Is the table proportional?
inysia [295]
No. In order to be proportional, y must change directly with x.

Looking at the first two pieces of data, let's find the ratio between x and y.

2/5 and 3/6. These should be equivalent of the table is proportional.





5 0
3 years ago
Helpppppppppp meeee please
Artemon [7]

Answer:

<2 and <8

<3 and <5

Step-by-step explanation:

The Alternate Interior Angles Theorem states that, when two parallel lines are cut by a transversal , the resulting alternate interior angles are congruent .

This is my 100th question answered!

3 0
3 years ago
List of reading his cell phone and monthly service please try and sell offers a new phone for $50 in unlimited service for a mon
Shtirlitz [24]

Answer:

After 5 months the cost of the two phones and monthly service be the same.

Step-by-step explanation:

1st service cost = $50 + $40x, where "x" represents the number of months

2nd service cost = $50x

Now we have to find the number of months the cost of the two phones and monthly service be the same.

Now we have to equivate and find the value of x.

50x = 50 + 40x

Subtracting 40x from both sides, we get

50x - 40x = 50 + 40x - 40x

10x = 50

Dividing both sides by 10, we get

x = 50/10

x = 5

After 5 months the cost of the two phones and monthly service be the same.

Hope you will understand the concept.

Thank you.


3 0
3 years ago
You want to distribute 7 candies to 4 kids. If every kid must receive at least one candy, in how many ways can you do this?
puteri [66]

Answer:

15

Step-by-step explanation:

lets begin to set up this question. i personally find questions like these easiest when i begin to set up ideas to help my brain process it better, for example:

person a

person b

person c

person d

we know that each (person) must receive at least 1 candy. we also know that we have 7 candies. therefore if we want do draw this out :

person a- 1

person b- 1

person c- 1

person d -1

notice that we now have given away 4 of the 7 candies. now we have 3 candies left. we can simply:

person a- 2

person b-2

person c-2

person d- 1

but, keep in mind that there are still many more ways that we can distribute the candies to other kids. the question we are asked is how may ways can we do this. since i have already illustrated the question, you can either learn how to put this into an equation, or experiment how many variations there are. the answer, either way is 15.

4 0
3 years ago
√1521 = evaluate 390²
Digiron [165]

Answer:

the square root of 1521 is 39 and 390 squared is 152,100 if that helps you

7 0
3 years ago
Other questions:
  • I got a 100% on my quiz that is 15% of my grade. My grade is currently an 85 overall, What will my final grade be?
    14·2 answers
  • A dust bunny gathers dust at a rate of 11% per week. The dust bunny, Alfred, originally weighed 0.7 ounces. Write an equation th
    9·1 answer
  • Is the statement (3^5)^4 equal to (3^4)^5 ? explain the reasoning, DUE TOMORROW
    5·2 answers
  • The local ice cream shop offers 3 different types of cones and 15 different flavors of ice cream. How many possible ice cream co
    15·1 answer
  • A fruit company delivers its fruit in two types of boxes: large and small. A delivery of 3 large boxes and 5 small boxes has a t
    13·1 answer
  • One batch of walnut muffins uses
    5·1 answer
  • A rectangle has sides with lengths (x+5) and (x+6) . Find the perimeter
    7·1 answer
  • Please help me in this it's similar figures assessment​
    7·1 answer
  • IS THE PRODUCT OF 89 AND 20?​
    13·1 answer
  • What is the surface area of the rectangular prism?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!