The heights of adult men in America are normally distributed,
with a mean of 69.5 inches and a standard deviation of 2.68 inches.
The heights of adult women in America are also normally
distributed, but with a mean of 64.4 inches and a standard
deviation of 2.53 inches.
a) If a man is 6 feet 3 inches tall, what is his z-score (to two
decimal places)?
b) What percentage of men are SHORTER than 6 feet 3 inches? Round
to nearest tenth of a percent.
c) If a woman is 5 feet 11 inches tall, what is her z-score (to two
decimal places)?
d) What percentage of women are TALLER than 5 feet 11 inches? Round
to nearest tenth of a percent.
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What z-score separates the highest 3 percent of the standard normal distribution from the lower 97 percent (i.e. represents the 97th percentile)?
In: Math
Assume that you are planning to have a party at your house. You really would like to have the party outside in the sun, but there is a chance that it might rain. You have two decisions to make – whether or not you will watch the forecast and then whether to have the party inside or outside. If you choose to watch the forecast, it will either tell you that the weather will be sunny or that it will be rainy. If you choose to watch the forecast, you will not have to make the location decision until after you see the forecast. If you do not watch the forecast, you do not get to know what the forecast would have said had you watched it – you need to make the location decision without the knowledge of the forecast. However, the forecast is imperfect (probabilities are below). It also costs you some time, and you are already cutting it close in terms of getting ready.
Your task is to draw the decision tree for this situation, answer some questions about the decision tree, and recommend a course of action on the basis if your analysis.
The information you will need:
Probabilities (note that p(A|B) signifies the probability of event A given that event B has occurred – it is a conditional probability).
p(forecast says it will be sunny) = 0.95
p(it is sunny|forecast said it would be sunny) = 0.99
p(it is sunny|forecast said it would be rainy) = 0.15
p(sunny) = 0.948 [hint: this is to use on the branch of the tree where you decide not to watch the forecast]
Utilities (note that U(case X) represents the utility of case X)
U(watch forecast, party indoors, sunny weather) = 0.3
U(watch forecast, party indoors, rainy weather) = 0.4
U(watch forecast, outdoors, sunny weather) = 0.9
U(watch forecast, outdoors, rainy weather) = 0.0
U(do not watch forecast, indoors, sunny weather) = 0.4
U(do not watch forecast, indoors, rainy weather) = 0.5
U(do not watch forecast, outdoors, sunny weather) = 1.0
U(do not watch forecast, outdoors, rainy weather) = 0.1
(a) (10 points): Draw the decision tree for this problem. Include clear labels for all branches. Include all probabilities and utilities.
(b) (10 points): If you choose to watch the forecast and it says that the weather will be sunny, should you have the party indoors or outdoors? What is your expected utility for this choice?
(c) (5 points): What should your sequence of decisions be? In other words, should you watch the forecast? If you do watch the forecast, what is the optimal location decision for each of the two possible forecast reports? What is your expected utility for the overall decision situation?
d) (10 points): Analyzing a simple party problem might seem silly. However, the structure of this tree has many important applications in engineering. Think of a project management situation that could be described by this structure of decision tree. Write a one-paragraph description of the decision situation you think of (like the description at the beginning of this question), and re-draw the tree with new labels on the branches. You do not need to include any probabilities or utilities on your new tree.
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Assume that the number of new visitors to a website in one hour is distributed as a Poisson variable with λ = 4.0. What is the probability in any given hour that two or more new visitors will arrive at the website?
Round to four decimals and use leading zeros if necessary.
In: Math
Explain how a sample, a sampling distribution, and a population differ. What are the means and standard deviation for each of these?
In: Math
Suppose a friend of yours is hosting a wine tasting. His wine supply includes three different types of deluxe wine. All bottles come from the same winery and all wines were harvested in 2017. He currently owns 8 bottles of zinfandel, 10 bottles of merlot, and 12 bottles of cabernet. Throughout the wine tasting, your friend will only open a new bottle of wine when there are no other bottles of wine open at the time.
a. State any and all event definitions.
b. Suppose the wine tasting will consist of two bottles chosen at random. How many different sequences of offerings are there?
c. Create a tree diagram of the sample space and label all events and their corresponding probabilities.
d. What is the probability that all bottles in the wine tasting are of the same type of wine?
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One genetic disease was tested positive in both parents of one family. It has been known that any child in this family has a 25% risk of inheriting this disease. A family has three children. The probability of this family having at least one child who inherited this genetic disease is:
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In a population survey of patients in a rehabilitation hospital, the mean length of stay in the hospital was 12.0 weeks with a standard deviation equal to 1.0 week. The distribution was normally distributed. What is the percentile rank for each of the following z scores? Enter the percentile rank to the right of each z score. Assume a normal distribution.
a) 1.23 _____
b) 0.89 ______
c) -0.46 _____
d) -1.00 ______
In: Math
|
Cigarettes/Day |
Death Rate/1000/Year due to CHF |
Death Rate/1000/Year due to CHF |
|
0 |
0.01 |
0.008 |
|
1-14 |
0.27 |
0.11 |
|
15-24 |
1.23 |
1.15 |
|
25+ |
2.00 |
1.50 |
Your quality improvement Team is revisiting the following patient readmissions and would like to predict the number of readmissions based on the number of drugs administered.
In: Math
A real estate agent (Sue Bays Realty) wants tot study the relationship between the size of a house and its selling price. The table below presents the size in square feet and the selling price in thousands of dollars, for a sample of houses in a suburban neighborhood.
| Size (Square Feet) | Selling Price ($1000s) |
| 2521 | 400 |
| 2555 | 426 |
| 2735 | 428 |
| 2846 | 435 |
| 3028 | 469 |
| 3049 | 475 |
| 3198 | 488 |
| 3198 | 455 |
Calculate the correlation between these two variables.
Calculate the Predicted Value for each size/price value.
If a linear regression model were fit, what would the value of the slope and the value of the y-intercept be?
In: Math
|
CHF patients |
|||
|
Number of Drugs Administered |
Readmitted |
Not readmitted |
Total |
|
≥3 drugs |
200 |
40 |
240 |
|
<3 drugs |
100 |
900 |
1000 |
|
Total |
300 |
940 |
1240 |
In: Math
Describe why hypothesis testing is important to businesses?
In: Math
One month before the election, a poll of 670 randomly selected
voters showed 348 planning to vote for a certain candidate. A week
later it became known that he had had an extramarital affair, and a
new poll showed only 450 out of 1020 voters supporting him. Is
there a significant decrease in voters support for his
candidacy?
a) Write appropriate hypotheses.
b) Test the hypotheses, find the P-value and state your conclusion.
Use α = 0.01.
c) Create a 98% confidence interval for the change in voters
opinion, and interpret your interval.
d) Comment on your interval in relation to your conclusion from
b).
In: Math
Question is related to organisations and stakeholders. Different stakeholders have different expectations from the company. select a small/ medium enterprise and list 11 stakeholders related to the enterprise and their individual concerns.
In: Math
| Classes (Percentage) | No of Students |
| 0 < 10 | 10 |
| 10 < 20 | 20 |
| 20 < 30 | 25 |
| 30 < 40 | 15 |
| 40 < 50 | 20 |
| 50 < 60 | 35 |
| 60 < 70 | 45 |
| 70 < 80 | 10 |
| 80 < 90 | 15 |
| 90 < 100 | 5 |
2.1 Determine the:
2.1.1 Mean number of marks (1 mark)
2.1.2 Median number of marks
2.1.3 Modal number of marks
2.2 Calculate the standard deviation
In: Math