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
UNO [17]
2 years ago
15

. (0.5 point) We simulate the operations of a call center that opens from 8am to 6pm for 20 days. The daily average call waiting

times are reported below for these 20 simulated days: 24.16 20.17 14.60 19.79 20.02 14.60 21.84 21.45 16.23 19.60 17.64 16.53 17.93 22.81 18.05 16.36 15.16 19.24 18.84 20.77 Due to a budget cut, the call center has now to downsize and the simulation model is used to predict the effect. We again simulate the call center for 20 days and now the daily average call waiting times are: 19.81 18.39 24.34 22.63 20.20 23.35 16.21 21.73 17.18 18.98 19.35 18.41 20.57 13.00 17.25 21.32 23.29 22.09 12.88 19.27 Compute a 95% t-confidence interval to decide if the change in the call waiting time is statistically significant.
Mathematics
1 answer:
SashulF [63]2 years ago
6 0

Answer:

The 95% t-confidence interval for the difference in mean is approximately (-2.61, 1.16), therefore, there is not enough statistical evidence to show that there is a change in waiting time, therefore;

The change in the call waiting time is not statistically significant

Step-by-step explanation:

The given call waiting times are;

24.16, 20.17, 14.60, 19.79, 20.02, 14.60, 21.84, 21.45, 16.23, 19.60, 17.64, 16.53, 17.93, 22.81, 18.05, 16.36, 15.16, 19.24, 18.84, 20.77

19.81, 18.39, 24.34, 22.63, 20.20, 23.35, 16.21, 21.73, 17.18, 18.98, 19.35, 18.41, 20.57, 13.00, 17.25, 21.32, 23.29, 22.09, 12.88, 19.27

From the data we have;

The mean waiting time before the downsize, \overline x_1 = 18.7895

The mean waiting time before the downsize, s₁ = 2.705152

The sample size for the before the downsize, n₁ = 20

The mean waiting time after the downsize, \overline x_2 = 19.5125

The mean waiting time after the downsize, s₂ = 3.155945

The sample size for the after the downsize, n₂ = 20

The degrees of freedom, df = n₁ + n₂ - 2 = 20 + 20  - 2 = 38

df = 38

At 95% significance level, using a graphing calculator, we have; t_{\alpha /2} = ±2.026192

The t-confidence interval is given as follows;

\left (\bar{x}_{1}- \bar{x}_{2}  \right )\pm t_{\alpha /2}\sqrt{\dfrac{s_{1}^{2}}{n_{1}}+\dfrac{s_{2}^{2}}{n_{2}}}

Therefore;

\left (18.7895- 19.5152 \right )\pm 2.026192 \times \sqrt{\dfrac{2.705152^{2}}{20}+\dfrac{3.155945^2}{20}}

(18.7895 - 19.5125) - 2.026192*(2.705152²/20 + 3.155945²/20)^(0.5)

The 95% CI = -2.6063 < μ₂ - μ₁ < 1.16025996668

By approximation, we have;

The 95% CI = -2.61 < μ₂ - μ₁ < 1.16

Given that the 95% confidence interval ranges from a positive to a negative value, we are 95% sure that the confidence interval includes '0', therefore, there is sufficient evidence that there is no difference between the two means, and the change in call waiting time is not statistically significant.

You might be interested in
Prove that every integer greater than 7 can be written by using 3's and 5's only. that is, for every n &gt; 7 there exist non-ne
Taya2010 [7]
An integer may be a multiple of 3.
An integer may be 1 greater than a multiple of 3.
An integer may be 2 greater than a multiple of 3.

It is redundant to say an integer is 3 greater than a multiple of 3 (that's just a multiple of 3, we've got it covered).  Same for 4, 5, 6, 7...

Let's consider a number which is a multiple of 3.  Clearly, we can write 3+3+3+3+... until we reach the number.  It can be written as only 3's.

Let's consider a number which is 2 greater than a multiple of 3.  If we subtract 5 from that number, it'll be a multiple of 3.  That means we can write the number as 5+3+3+3+3+...  Of course, the number must be at least 8.

Let's consider a number which is 1 greater than a multiple of 3.  If we subtract 5 from that number, it'll be 2 greater than a multiple of 3.  If we subtract another 5, it'll be a multiple of 3.  That means we can write the number as 5+5+3+3+3+3+...  Of course, the number must be at least 13.

That's it.  We considered all the numbers.  We forgot 9, 10, 11, and 12, but these are easy peasy.

Beautiful question.
4 0
3 years ago
Question 4 pls thanks, I will mark Brainliest
xxTIMURxx [149]

the second one.

Step-by-step explanation:

sjisidjdododpdpddod

6 0
2 years ago
A college student took 4 courses last semester. His final grades, along with the credits each class is worth, are as follow: A (
NikAS [45]

Answer:

A college student took 4 courses last semester. His final grades, along with the credits each class is worth, are as follow: A (3), B (4), C (2), and D (3). The grading system assigns quality points as follows: A: 4; B: 3; C: 2; D: 1; and F: 0. Find the student’s GPA for this semester. Round your answer to the nearest thousandth.

another way is

This is a weighted average question. You are going to "weight" each course by the number of credits it is worth and then divide by the total number of credits. In other words, you are going to multiply each grade (A=4, B=3) by the number of credits attached to that grade. This will ensure that the courses that have more credits count more in the overall average. Then you are going to divide by the total number of credits to get the overall GPA.

So,

(3*4 + 4*3 + 2 *2 + 3*1)/(3+4+2+3) = GPA

Step-by-step explanation:

bran-list please

6 0
2 years ago
What is the measure of ABC?
lesantik [10]

Answer:

Step-by-step explanation:

85 degrees. Step-by-step explanation: From the diagram, it is clearly visible that the angle ∠ABC is formed by intersections of two chords AE and CD of the circle.

8 0
2 years ago
Read 2 more answers
Please help me haha!
DanielleElmas [232]

Answer:

w=4

Step-by-step explanation:

2+6=8

8/2=4

w is 4 because half of 8 is 4.

Honestly this is my best guess idk.

5 0
3 years ago
Read 2 more answers
Other questions:
  • Creating box plots
    15·1 answer
  • Carlota wrote the equation y + 1 = 2 (x - 3) for the line passing through the points (-1, 3) and (2, 9). Explain and correct her
    13·1 answer
  • Two sides of an acute triangle measure 5 inches and 8 inches. The length of the longest side is unknown.
    10·2 answers
  • How does 2^3 times 4^3= 2^9
    9·2 answers
  • A construction company needs to remove 4 1 6 tons of dirt from a construction site. They can remove 8 9 tons of dirt each hour.
    10·1 answer
  • 4. What is the measure of angle xº?
    7·1 answer
  • A. How many ways can you make a code of 3<br> digits if any number can be repeated?
    12·1 answer
  • What is 3.435 rounded to the nearest hundredth?<br> Submit
    6·1 answer
  • Based on the diagram below, what is the interior measure of ∠Y ?
    11·1 answer
  • 3/10 - 1/5=<br><br><br> Find the missing fraction.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!