In a particular community, 65 percent of households include at least one person who has graduated from college. You randomly sample 100 households in this community. Let X=the number of households including at least one college graduate.
What is the probability that at most 82 households include at least one college graduate?
In: Statistics and Probability
A stockbroker has a large number of clients. The proportion of clients with whom she does not communicate during a given month has the beta distribution with parameters α = 6 and β = 2. Determine the probability that, during a given month, the percentage of clients with whom the broker does not communicate will be
a) at least 60%.
b) between 70% and 80%.
In: Statistics and Probability
A die is weighted so that rolling a 1 is two times as likely as rolling a 2, a 2 is two times likely as rolling a 3, a 3 is two times as likely as rolling a 4, a 4 is two times a likely as rolling a 5, and a 5 is two times as likely as rolling a 6. What is the probability of rolling an even number?
In: Math
We have 95 students in a class. Their abilities/eagerness are uniform randomly distributed on a scale between 1 and 4; and at the end of the class they will be judged right and they will receive a grade corresponding to their ability/eagerness (corresponding to their performance). What is the probability that the class average will be between 2.8 and 4? How would this number change (if it does) for 120 students?
In: Math
Problem 4) Five coins are flipped. The first four coins will land on heads with probability 1/4. The fifth coin is a fair coin. Assume that the results of the flips are independent. Let X be the total number of heads that result.
(hint: Condition on the last flip).
a) Find P(X=2)
b) Determine E[X]
In: Math
18. TRUE OF FALSE: Payback is the number of years it takes for the project to pay for itself, without regard to the time value of money.
19. TRUE OF FALSE: The high profitability index means that the company will achieve the highest NPV per dollar of investment.
20. TRUE OR FALSE: NPV is the best method for capital rationing situations.
21. TRUE OR FALSE: In some cases, NPV and IRR will rank projects differently.
22. TRUE OR FALSE: Under capital rationing situations, a firm will not undertake all projects that are viewed as profitable; only those projects that will return the highest NPV for the limited capital available should be undertaken.
23. TRUE OR FALSE: In choosing between 2 mutually exclusive projects where only one can be undertaken because of limited capital, the project with the highest profitability index should be undertaken.
24. In deciding or choosing among capital projects to undertake:
a. Net Present value is the difference between investment cash outflows and cash inflows taking into account the time value of money using a discount rate, hurdle rate, or cost of capital.
b. Internal rate of return is the discount rate computed such that the net present value of the investment is zero.
c. Profitability index facilitates comparison of different sized investments.
d. All of the above is correct.
25. NPV and IRR are the soundest investment rules from a shareholder wealth maximization perspective:
a. Using NPV and IRR as the basis of choosing between mutually exclusive projects, if one accepted, the other must be rejected.
b. Using NPV and IRR as the basis of choosing between mutually exclusive projects, a project with an initial outlay of $1,000, Year end cash flow of $1,000, IRR of 20% and NPV of $91 will prevail over a project with an initial outlay of $50, Year end cash flow of $100, IRR of 100% and NPV of 41.
c. Using IRR, the choice in (b) above will be the opposite, that is, the project with an IRR of 100% will prevail.
d. All of the statements above are correct.
In: Finance
PLEASE ANSWER JUST QUESTION i, j, l. Thanks
Confidence interval for a mean and one-sample t-test. As the world warms, the geographic ranges of species might shift toward cooler areas. Chen et al. (2011) studied recent changes in the highest elevation at which species occur. Typically, higher elevations are cooler than lower elevations. Below are the changes in highest elevation for 31 taxa, in meters, over the late 1900s and early 2000s. (Many taxa were surveyed, including plants, vertebrates, and arthropods.) Positive numbers indicate upward shifts in elevation, and negative numbers indicate shifts to lower elevations. The values are displayed in the accompanying figure.
58.9, 7.8, 108.6,
44.8, 11.1, 19.2,
61.9, 30.5 12.7,
35.8, 7.4, 39.3,
24.0, 62.1, 24.3,
55.3 32.7, 65.3, −19.3,
7.6, −5.2, −2.1,
31.0, 69.0 88.6,
39.5, 20.7, 89.0,
69.0, 64.9, 64.8
a. What is the
sample size n?
b. What is the mean of these data points? Remember to give the units.
c. What is the standard deviation of elevational range shift? (Give the units as well.)
d. What is the standard error of the mean for these data?
e. How many degrees of freedom will be associated with a confidence interval and a onesample t-test for the mean elevation shift?
f. What value of α is needed for a 95% confidence interval?
g. What is the critical value of t for this α and number of degrees of freedom?
h. What assumptions are necessary to use the confidence interval calculations in this chapter?
i. Calculate the 95% confidence interval for the mean using these data.
j. For the one-sample t-test, write the appropriate null and alternative hypotheses.
k. Calculate the test statistic t for this test.
l. What assumptions are necessary to do a one-sample t-test?
m. Describe the P-value for this test as accurately as you can.
n. Did species change their highest elevation on average?
In: Statistics and Probability
In this assignment, the program will keep track of the amount of rainfall for a 12-month period. The data must be stored in an array of 12 doubles, each element of the array corresponds to one of the months. The program should make use of a second array of 12 strings, which will have the names of the months. These two arrays will be working in parallel. The array holding the month names will be initialized when the array is created using an initialization list (could also be created as an array of constants). The second array will hold doubles which will be the total rainfall for each month. Using a function, the program will prompt the user for the rainfall for each month (using both arrays) and store the value entered into the array with the rainfall totals; the other is used to display which month the program is asking for the rainfall total.
The output of the program will display the following once the data is all entered:
The program must have the following functions:
Pseudocode must be provided in the comment block at the top of the file. This must be done with Visual Studio 2019 comm edition C++
In: Computer Science
Table 3: Cars Sold per Day
|
# Per Day |
# Days |
|
0 |
35 |
|
1 |
75 |
|
2 |
55 |
|
3 |
25 |
|
4 |
10 |
For example, 35 of the days, no cars were sold. For 75 days one was sold.
In: Statistics and Probability
Let p be the (unknown) proportion of males in a town of 100, 000 residents. A political scientist takes a simple random sample of 100 residents from this town.
(a) Write down the exact pmf, as well as an approximate pmf, for the number of males in the sample. (They should both depend on p).
(b) If the number of males in the sample is 55 or more, the political scientist will claim that there are more males than females in the town. If the number of males in the sample is less than 55, he/she will claim that the number of males in the town is smaller or equal to that of females. What is approximately the probability that his/her claim will be correct if the true proportion of males in the town, p, is 50%? What if p = 55%?
(c) Report an approximate 68% confidence interval for p if 65 of the 100 residents in the sample are male.
In: Math