Questions
The table below shows the number of male and female students enrolled in nursing at a...
The table below shows the number of male and female students enrolled in nursing at a particular university for a recent semester.
(a) Find the probability that a randomly selected student is male, given that the student is a nursing major
(b) Find the probability that a randomly selected student is a nursing major, given that the student is male.
| Nursing Majors | Non-nursing majors | Total | |
| Males | 97 | 1082 | 1179 |
| Females | 750 | 1633 | 2383 |
| Total | 847 | 2715 | 3562 |
(a) Find the probability that a randomly selected student is male, given that the student is a nursing major
The probability is _______ .
(Round to three decimal places as needed.)
In: Math
The Westchester Chamber of Commerce periodically sponsors public service seminars and programs. Currently, promotional p...
The Westchester Chamber of Commerce periodically sponsors public service seminars and programs. Currently, promotional plans are under way for this year's program. Advertising alternatives include television, radio, and online. Audience estimates, costs, and maximum media usage limitations are as shown: Constraint Television Radio Online Audience per advertisement 110,000 18,000 30,000 Cost per advertisement $1,500 $250 $500 Maximum media usage 11 21 13 To ensure a balanced use of advertising media, radio advertisements must not exceed 50% of the total number of advertisements authorized. In addition, television should account for at least 10% of the total number of advertisements authorized.
(a) If the promotional budget is limited to $23,000, how many commercial messages should be run on each medium to maximize total audience contact? If your answer is zero enter “0”. Advertisement Alternatives No of commercial messages Television Radio Online What is the allocation of the budget among the three media? Advertisement Alternatives Budget ($) Television $ Radio $ Online $ What is the total audience reached?
(b) By how much would audience contact increase if an extra $100 were allocated to the promotional budget? Round your answer to the nearest whole number. Increase in audience coverage of approximately
In: Math
Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is...
Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.74.
(a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 20 specimens from the seam was 4.85.
(b) Compute a 98% CI for true average porosity of another seam based on 13 specimens with a sample average porosity of 4.56.
(c) How large a sample size is necessary if the width of the 95% interval is to be 0.4?
(d) What sample size is necessary to estimate true average porosity to within 0.21 with 99% confidence?
In: Math
1. Which of the following is not a characteristic of the normal probability distribution? a. The...
1. Which of the following is not a characteristic of the normal probability distribution?
|
a. |
The distribution is symmetrical |
|
|
b. |
The mean of the distribution can be negative, zero, or positive |
|
|
c. |
The standard deviation must be 1 |
|
|
d. |
The mean, median, and the mode are equal |
2. If , n = 12, and the slope equals 0.5, then the y-intercept of the least squares line is b0 = 276.08.
True
False
3. The coefficient of correlation r is a number that indicates the direction and the strength of the linear relationship between the dependent variable y and the independent variable x.
True
False
4. The function that defines the probability distribution of a continuous random variable is a
|
a. |
uniform function. |
|
|
b. |
normal function. |
|
|
c. |
either normal of uniform depending on the situation. |
|
|
d. |
probability density function. |
In: Math
It is common in many industrial areas to use a filling machine to fill boxes full of product.
It is common in many industrial areas to use a filling machine to fill boxes full of product. This occurs in the food industry as well as other areas in which the product is used in the home, for example, detergent. These machines are not perfect, and indeed they may A, fill to specification, B, underfill, and C, overfill. Generally the practice of underfilling is that which one hopes to avoid. Let P(C) = 0.034 while P(A) = 0.960.
(a) What is the probability that the box is underfilled, P(B)?
(b) What is the probability that the machine does not overfill?
(c) What is the probability that the machine either overfills or underfills?
In: Math
Your manager is trying to determine what forecasting method to use. Based upon the following historical...
Your manager is trying to determine what forecasting method to use. Based upon the following historical data, calculate the following forecast and specify what procedure you would utilize.
| MONTH | ACTUAL DEMAND | ||
| 1 | 59 | ||
| 2 | 62 | ||
| 3 | 64 | ||
| 4 | 65 | ||
| 5 | 73 | ||
| 6 | 75 | ||
| 7 | 75 | ||
| 8 | 78 | ||
| 9 | 78 | ||
| 10 | 81 | ||
| 11 | 82 | ||
| 12 | 85 | ||
a. Calculate the simple three-month moving average forecast for periods 4–12. (Round your answers to 3 decimal places.)
| Month | Three-Month Moving Average |
|
| 4 | ||
| 5 | ||
| 6 | ||
| 7 | ||
| 8 | ||
| 9 | ||
| 10 | ||
| 11 | ||
| 12 | ||
b. Calculate the weighted three-month moving average for periods 4–12 using weights of 0.40 (for the period t−1); 0.50 (for the period t−2), and 0.10 (for the period t−3). (Do not round intermediate calculations. Round your answers to 1 decimal place.)
| Month | Three-Month Weighted Moving Average |
|
| 4 | ||
| 5 | ||
| 6 | ||
| 7 | ||
| 8 | ||
| 9 | ||
| 10 | ||
| 11 | ||
| 12 | ||
c. Calculate the single exponential smoothing forecast for periods 2–12 using an initial forecast (F1) of 58 and an α of 0.40. (Do not round intermediate calculations. Round your answers to 3 decimal places.)
| Month | Single Exponential Smoothing Forecast |
|
| 2 | ||
| 3 | ||
| 4 | ||
| 5 | ||
| 6 | ||
| 7 | ||
| 8 | ||
| 9 | ||
| 10 | ||
| 11 | ||
| 12 | ||
d. Calculate the exponential smoothing with trend component forecast for periods 2–12 using an initial trend forecast (T1) of 1.50, an initial exponential smoothing forecast (F1) of 57, an α of 0.40, and a δ of 0.40. (Do not round intermediate calculations. Round your answers to 3 decimal places.)
| Month | Exponential Smoothing with Trend |
|
| 2 | ||
| 3 | ||
| 4 | ||
| 5 | ||
| 6 | ||
| 7 | ||
| 8 | ||
| 9 | ||
| 10 | ||
| 11 | ||
| 12 | ||
e-1. Calculate the mean absolute deviation (MAD) for the forecasts made by each technique in periods 4–12. (Do not round intermediate calculations. Round your answers to 3 decimal places.)
| Mean Absolute Deviation |
|
| Three-month moving average | |
| Three-month weighted moving average | |
| Single exponential smoothing forecast | |
| Exponential smoothing with trend | |
e-2. Which forecasting method is best?
| Single exponential smoothing forecast | |
| Three-month weighted moving average | |
| Three-month moving average | |
| Exponential smoothing with trend forecast |
In: Math
A data set includes data from student evaluations of courses. The summary statistics are n=93, x...
A data set includes data from student evaluations of courses. The summary statistics are n=93, x overbar equals=4.08 sequals=0.65. Use a 0.10 significance level to test the claim that the population of student course evaluations has a mean equal to 4.25
Assume that a simple random sample has been selected. Identify the null and alternative hypotheses, test statistic, P-value, and state the final conclusion that addresses the original claim.
In: Math
Seth Bullock, the owner of Bullock Gold Mining, is evaluating a new gold mine in South Dakota. Dan Dority, the company’s...
Seth Bullock, the owner of Bullock Gold Mining, is evaluating a new gold mine in South Dakota. Dan Dority, the company’s geologist, has just finished his analysis of the mine site. He has estimated that the mine would be productive for eight years, after which the gold would be completely mined. Dan has taken an estimate of the gold deposits to Alma Garrett, the company’s financial officer. Alma has been asked by Seth to perform an analysis of the new mine and present her recommendation on whether the company should open the new mine. Alma has used the estimates provided by Dan to determine the revenues that could be expected from the mine. She has also projected the expense of opening the mine and the annual operating expenses. If the company opens the mine, it will cost $635 million today, and it will have a cash outflow of $45 million nine years from today in costs associated with closing the mine and reclaiming the area surrounding it. The expected cash flows each year from the mine are shown in the table. Bullock Mining has a required return of 12 percent on all of its gold mines.
|
Year |
Cash Flow |
|
0 1 2 3 4 5 6 7 8 9 |
−$635,000,000 89,000,000 105,000,000 130,000,000 173,000,000 205,000,000 155,000,000 145,000,000 122,000,000 − 45,000,000 |
-
Construct a spreadsheet to calculate the payback period, internal rate of return, modified internal rate of return, and net present value of the proposed mine.
-
Based on your analysis, should the company open the mine?
In: Math
Find the standard deviation, s, of sample data summarized inthe frequency distribution table below by...
Find the standard deviation, s, of sample data summarized in the frequency distribution table below by using the formula below, where x represents the class midpoint, f represents the class frequency, and n represents the total number of sample values. Also, compare the computed standard deviation to the standard deviation obtained from the original list of data values, 11.1
\(S=\sqrt{\frac{n\left[\sum\left(1 \cdot x^{2}\right)\right]-\left[\sum(t+x)\right]^{2}}{n(n-1)}}\)
| Interval | 30.36 | 37-43 | 44.50 | 51-57 | 53.84 | 65-71 | 72.78 |
|---|---|---|---|---|---|---|---|
| Frequency | 2 | 2 | 1 | 1 | 13 | 28 | 30 |
Standard deviations=
(Round to one decimal place as needed.)
Consider a difference of 20% between two values of a standard deviation to be significant. How does this computer values compare with the given standard deviation 11.1?
the computer values is not significantly different from the given value
the computer values is significantly greater than the given value
the computer values is significantly less than the given values
In: Math
Find the indicated IQ score. The graph to the right depicts IQ scores of adults, and...
Find the indicated IQ score. The graph to the right depicts IQ scores of adults, and those scores are normally distributed with a mean of 100 and a standard deviation of 15.
The indicated IQ score, x, is _______ (Round to one decimal place as needed.)
Find the area of the shaded region. The graph depicts the standard normal distribution of bone density scores with mean 0 and standard deviation 1.
The area of the shaded region is _______ (Round to four decimal places as needed.)
Find the area of the shaded region. The graph depicts the standard normal distribution of bone density scores with mean 0 and standard deviation 1.
The area of the shaded region is _______ (Round to four decimal places as needed.)
In: Math
A group of students estimated the length of one minute without reference to a watch or...
A group of students estimated the length of one minute without reference to a watch or clock, and the times (seconds) are listed below. Use a 0.10 significance level to test the claim that these times are from a population with a mean equal to 60 seconds. Does it appear that students are reasonably good at estimating one minute?
71 79 39 63 41 27 59 66 68 46 66 72 91 87 63
What are the null and alternative hypotheses?
In: Math
There are two traffic lights on a commuter's route to and from work. Let X1 be...
There are two traffic lights on a commuter's route to and from work. Let X1 be the number of lights at which the commuter must stop on his way to work, and X2 be the number of lights at which he must stop when returning from work. Suppose that these two variables are independent, each with the pmf given in the accompanying table (so X1, X2 is a random sample of size n = 2).
| x1 | 0 | 1 | 2 | μ = 1, σ2 = 0.6 | |
| p(x1) | 0.3 | 0.4 | 0.3 |
(a) Determine the pmf of To = X1 + X2.
| to | 0 | 1 | 2 | 3 | 4 |
| p(to) |
(b) Calculate
μTo.
μTo
=
How does it relate to μ, the population mean?
μTo = ·
μ
(c) Calculate
σTo2.
| σTo2 | = |
How does it relate to σ2, the population
variance?
σTo2
= · σ2
(d) Let X3 and X4 be the
number of lights at which a stop is required when driving to and
from work on a second day assumed independent of the first day.
With To = the sum of all four
Xi's, what now are the values of
E(To) and
V(To)?
| E(To) = | |
| V(To) = |
(e) Referring back to (d), what are the values of
P(To = 8) and P(To ≥ 7)
[Hint: Don't even think of listing all possible outcomes!] (Enter your answers to four decimal places.)
|
P(To = 8) = |
|||||||||||||||||||||||||||||||||
|
P(To ≥ 7) = |
There are two traffic lights on a commuter's route to and from work. Let X1 be the number of lights at which the commuter must stop on his way to work, and X2 be the number of lights at which he must stop when returning from work. Suppose that these two variables are independent, each with the pmf given in the accompanying table (so X1, X2 is a random sample of size n = 2).
(a) Determine the pmf of To = X1 + X2.
P(To = 8) and P(To ≥ 7) [Hint: Don't even think of listing all possible outcomes!] (Enter your answers to four decimal places.)
|
In: Math
A random sample of 40 students has a mean annual earnings of $3120
A random sample of 40 students has a mean annual earnings of $3120.
Assume the population standard deviation, σ, is $677. (Section 6.1)
• Construct a 95% confidence interval for the population mean annual earnings of students.
Margin of error, E._______ Confidence interval: _______ <μ< _______
• If the number of students sampled was reduced to 25 and the level of confidence remained at 95%, what would be the new error margin and confidence interval?
Margin of error, E._______ Confidence interval: _______ <μ< _______
• Did the confidence interval increase or decrease and why?
• If the number of students sampled was increased to 100 and the level of confidence remained at 95%, what would be the new confidence interval?
Margin of error, E._______ Confidence interval: _______ <μ< _______
• Did the confidence interval increase or decrease and why?
In: Math
Silicone implant augmentation rhinoplasty is used to correct congenital nose deformities.
Silicone implant augmentation rhinoplasty is used to correct congenital nose deformities. The success of the procedure depends on various biomechanical properties of the human nasal periosteum and fascia. An article reported that for a sample of 20 (newly deceased) adults, the mean failure strain% was 26.0, and the standard deviation was 3.5.
(a) Assuming a normal distribution or failure strain, estimate true average strain in a way that conveys information about precision and reliability. confidence interval. Round your answers to two decimal places.)
(b) Predict the strain for a single adult in a way that conveys information about precision and reliability. (Use a 95% prediction interval. Round your answers to two decimal places.)
How does the prediction compare to the estimate calculated in part (a)?
The prediction interval is much wider than the confidence interval in part (a)
The prediction interval is much narrower than the confidence interval in part (a)
The prediction interval is the same as the confidence interval in part (a)
In: Math