Question 1:- A potential investor collected attendance data over a period of 49 days at the North Mall and South Mall theaters in order to determine the difference between the average daily attendances. The North Mall Theater averaged 720 patrons per day with a variance of 100, while the South Mall Theater averaged 700 patrons per day with a variance of 96. Develop an interval estimate for the difference between the average daily attendances at the two theaters. Use a confidence coefficient of 0.95.
Question 2:-Zip, Inc. manufactures Zip drives on two different manufacturing processes. Because the management of this company is interested in determining if process 1 takes less manufacturing time, they selected independent random samples from each process. The results of the samples are shown below. (20 points)
Process 1 Process 2
Sample size 27 22
Sample mean (in minutes) 10 14
Sample variance 16 25
Question 3:-
Shown below is a portion of computer output for a regression analysis relating to Y (dependent variable) and X (independent variable). (20 points)
ANOVA
df SS
Regression 1 115.064
Residual 13 82.936
Total
Coefficients Standard Error
Intercept 15.532 1.457
x -1.106 0.261
a. Perform a t-test using the p-value approach and determine whether x and y are related. Let α = .05.
b. Using the p-value approach, perform an F test, and determine whether x and y are related.
c. Compute the coefficient of determination and fully interpret its meaning. Be specific.
In: Statistics and Probability
A shingle of dimensions a = 12 inch ✕ b = 24 inch has to withstand the lift force created by winds of up to 86 miles per hour. (Density of air = 1.2 kg/m3
In: Physics
If we wish to map an area 3.1 miles × 500 feet with 2-foot contours, (Photo scale is 1″= 500 feet); how many photos are required to properly cover the area?
In: Civil Engineering
Exhibit L.1 reports the multivariate odds ratios comparing each category to women who never had an induced abortion and had at least one pregnancy. Researchers were able to interview 845 out of 1,011 (83.5 percent) of the eligible cases and 961 out of 1,239 (78 per- cent) of the eligible controls. Of the cases, only 689 (81.5 percent) had complete information on abortion history, compared to 781 (81.3 per- cent) of the eligible controls.
|
Abortion History |
Cases |
Controls |
Crude OR2 |
Multivariate OR (95% CI)3 |
|
Ever had abortion |
210 |
201 |
1.5 (1.2–1.9) |
|
|
1 abortion only |
150 |
142 |
1.5 (1.1–2.0) |
|
|
2+ abortions |
60 |
59 |
1.6 (1.0–2.4) |
|
|
Age at first abortion |
||||
|
<18 |
20 |
15 |
2.5 (1.1–5.7) |
|
|
18–19 |
34 |
36 |
1.7 (1.0–3.0) |
|
|
20–29 |
115 |
123 |
1.3 (1.0–1.7) |
|
|
30+ |
41 |
27 |
2.1 (1.2–3.5) |
|
|
Timing of first abortion |
||||
|
Before 1st birth |
69 |
76 |
1.4 (1.0–2.0) |
|
|
After 1st birth |
74 |
63 |
1.5 (1.0–2.2) |
|
|
Never gave birth |
67 |
62 |
1.7 (1.2–2.6) |
|
|
Never had abortion |
479 |
580 |
–– |
|
|
Never had an abortion and at least one pregnancy1 |
466 |
564 |
–– |
Note: 1. Estimated from the data. 2. Multivariate OR adjusts for age, family history of breast cancer, religion, age at first pregnancy. 3. Both crude and multivariate odds ratio estimates risk relative to women with a least one pregnancy who never had an induced abortion. Source: Daling et al. (1994).
Calculate the crude odds ratios for each of the abortion history strata in Exhibit L.1. What is the overall increased risk of abortion after adjusting for several covariates?
In: Advanced Math
Given the following linear optimization model, transform this model into the required form and solve using Solver.
Objective function: 8.2? + 7.0? + 6.5? + 9.0? = ??????? ????
Constraints: 6? + 2? + 5? + 7? ≥ 820
?/? + ? + ? + ? ≥ 0.3
? + ? ? + ? ≥ 0.2
? ≥ ? + D
Please Use Excel
In: Statistics and Probability
Consider the following hypotheses.
Upper H0: p≤0.25
Upper H1: p>0.25
Given that p=0.3, n=110, and α=0.05 answer the following questions.
a. What conclusion should be drawn?
b. Determine the p-value for this test.
In: Statistics and Probability
A binomial probability experiment is conducted with the given parameters. Compute the probability of x successes in the n independent trials of he experiment.
n=9, p=0.3, x≤3
The probabity of x≤3 succenses is _______ (Round to four decimal places as needed.)
In: Statistics and Probability
If a cylindrical steel pressure vessel has a 400-mm inner radius and 8-mm-thick walls. Find the change (mm) in the inner radius when the vessel is pressurized to 1.2 MPa. Use E = 200 GPa and v = 0.3 for steel.
In: Civil Engineering
|
The NuPress Valet Co. has an improved version of its hotel stand. The investment cost is expected to be $72 million and will return $13.5 million for 5 years in net cash flows. The ratio of debt to equity is 1 to 1. The cost of equity is 13%, the cost of debt is 9%, and the tax rate is 34%. The appropriate discount rate, assuming average risk, is: |
| 9% | |
| 9.47% | |
| 8.65% | |
| 13% | |
| 10.5% |
In: Finance
In: Operations Management