Assume that the helium porosity (in percentage) of coal samples taken from any particular seam is normally distributed with true standard deviation 0.77.
(a) Compute a 95% CI for the true average porosity of a certain seam if the average porosity for 24 specimens from the seam was 4.85. (Round your answers to two decimal places.)
.................................. , .............................................
(b) Compute a 98% CI for true average porosity of another seam based on 10 specimens with a sample average porosity of 4.56. (Round your answers to two decimal places.)
....................................... , ............................................
(c) How large a sample size is necessary if the width of the 95% interval is to be 0.49? (Round your answer up to the nearest whole number.)............................. specimens
(d) What sample size is necessary to estimate true average porosity to within 0.23 with 99% confidence? (Round your answer up to the nearest whole number.) .....................specimens
You may need to use the appropriate table in the Appendix of Tables to answer this question.
In: Statistics and Probability
A political candidate has asked you to conduct a poll to
determine what percentage of people support her.
If the candidate only wants a 5% margin of error at a 95%
confidence level, what size of sample is needed?
In: Statistics and Probability
Consider the data labelled “problem 2”. It presents a
random sample of students scores (in percentage) obtained by
students in a standardized national test.
(i) Construct a 94% confidence interval on the fraction of students
who scored above 70% on the test. (10)
(ii) Test the claim that more than 35% of the students score higher
than 78% on the test. Write the hypotheses, identify
test-statistics and compute its value.
| 84 |
| 69.2 |
| 31.9 |
| 85.5 |
| 47.8 |
| 88.8 |
| 52.1 |
| 78.2 |
| 78.3 |
| 79.5 |
| 69.5 |
| 42.4 |
| 59.8 |
| 48.4 |
| 53.7 |
| 46.7 |
| 76.7 |
| 34.4 |
| 69.5 |
| 56.8 |
| 75.9 |
| 80 |
| 61.4 |
| 78.6 |
| 62.7 |
| 45.7 |
| 61.9 |
| 73.3 |
| 75.6 |
| 83.5 |
| 74.5 |
| 38.2 |
| 38.4 |
| 52.2 |
| 96.7 |
| 59.2 |
| 69.4 |
| 32.9 |
| 98 |
| 66.3 |
| 99 |
| 94.6 |
| 90.1 |
| 28.2 |
| 72.8 |
In: Statistics and Probability
given a 5.0 g sample of a vinegar having a mass percentage of acetic acid equal to 9.1%(m/m), calculate what volume of NaOH solution of molarity 0.82M will be necessary to threats this vinegar sample.
In: Chemistry
College officials want to estimate the percentage of students who carry a gun, knife, or other such weapon. A 90% confidence interval is desired where the interval is no wider than 5 percentage points? (a) How many randomly selected students must be surveyed if we assume that there is no available information that could be used as an estimate of p^. First Hint: note the question is limiting the "width" of the interval to 5 percentage points. Also, use at least five decimals places of accuracy with all values used in calculations. Answer: (b) How many randomly selected students must be surveyed if we assume that another study indicated that 7% of college students carry weapons. Answer:
In: Statistics and Probability
Coupon payments are fixed, but the percentage return that investors receive varies based on market conditions. This percentage return is referred to as the bond’s yield.
Yield to maturity (YTM) is the rate of return expected from a bond held until its maturity date. However, the YTM equals the expected rate of return under certain assumptions. Which of the following is one of those assumptions?
The bond has an early redemption feature.
The bond will not be called.
Consider the case of Blanche Inc.:
Blanche Inc. has 9% annual coupon bonds that are callable and have 18 years left until maturity. The bonds have a par value of $1,000, and their current market price is $1,100.35. However, Blanche Inc. may call the bonds in eight years at a call price of $1,060. What are the YTM and the yield to call (YTC) on Blanche Inc.’s bonds?
|
Value |
|
|---|---|
| YTM | |
| YTC |
If interest rates are expected to remain constant, what is the best estimate of the remaining life left for Blanche Inc.’s bonds?
5 years
10 years
8 years
13 years
If Blanche Inc. issued new bonds today, what coupon rate must the bonds have to be issued at par?
In: Finance
13 Selling is what percentage of listening?
14 When negotiating a salary, countering an increase by what percentage is normal?
15 When considering an appropriate salary, what do most companies include in their salary packages that you should also take into consideration before accepting or declining?
16 List 3 new things you learned from Celinda.
17 Data shows that in the majority of cases, people who negotiate for a higher salary get one!
Select one:
True
False
18 How long should you take to consider an offer:
19-The salesperson who listens well to the prospect will find that prospect will listen well to the salesperson. And that translates into more sales.
Select one:
True
False
20 Nonverbal messages are as important as verbal ones.
Select one:
True
False
In: Accounting
A researcher wishes to estimate the percentage of adults who support abolishing the penny. What size sample should be obtained if he wishes the estimate to be within 3 percentage points with 95% confidence if (a) he uses a previous estimate of 24%? (b) he does not use any prior estimates? n=?
In: Statistics and Probability
Mary owes an amount of $1,460 on her credit card. The annual percentage rate (APR) is 3%, compounded monthly. Her minimum monthly payment is $20.
a. If she makes only this minimum payment, how long will it take to repay the card balance (assuming no more charges are made)?
b. If she makes the minimum payment plus $10 extra each month (for a total of $30), how long will it take to repay the card balance?
In: Economics
How does translation exposure affect a business with a high percentage of business conducted by subsidiaries? What factors come into play?
In: Finance