Questions
The Centers for Disease Control reported the percentage of people 18 years of age and older...

The Centers for Disease Control reported the percentage of people 18 years of age and older who smoke (CDC website, December 14, 2014). Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of .30.

a. How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of .02 (to the nearest whole number)? Use 95% confidence.

b. Assume that the study uses your sample size recommendation in part (a) and finds 520 smokers. What is the point estimate of the proportion of smokers in the population (to 4 decimals)?

c. What is the 95% confidence interval for the proportion of smokers in the population (to 4 decimals)?

( ,  

In: Statistics and Probability

Researchers believe that a higher percentage of males are afflicted with cysturina than females. Suppose of...

  1. Researchers believe that a higher percentage of males are afflicted with cysturina than females. Suppose of the 50 individuals, 15 were females and the remainder were males. Using 99% confidence, estimate the proportion of females with cysturina. Then estimate the proportion of females afflicted with cysturina at 96% confidence.

In: Statistics and Probability

How much PE does glucose have compared to gasoline (express as a percentage)?

How much PE does glucose have compared to gasoline (express as a percentage)?

In: Chemistry

$1M is available to invest in S or B. The percentage yield on each investment depends...

$1M is available to invest in S or B. The percentage yield on each investment depends on whether the econ has a good or bad year.

Econ has a Good year    Econ has a Bad year

Yield on S    22% of 1M 10% of 1M

   (i.e. $220,000)    ($100,000)

Yield on B 16% of 1M 14% of 1M

($160,000) ($140,000)

It is equally likely (50%) that the econ will have a good or bad year.

For $10,000, a firm can be hired to forecast the state of the econ. The firm's forecasts have the following probabilities:

p(Good forecast | Econ is good) = .8

p(GF | EIB) = .2

It is equally likely (50%) for EIG & EIB to occur

a) Calculate the following:

p(EIG | GF) =

p(EIB | GF) =

p(EIG | BF) =

p( EIB | BF) =

b) Draw a decision tree to determine to invest in S or B to maximize expected profits. Should the firm be hired?

c) What are the values of the EVSI and EVPI?

In: Statistics and Probability

The home run percentage is the number of home runs per 100 times at bat. A...

The home run percentage is the number of home runs per 100 times at bat. A random sample of 43 professional baseball players gave the following data for home run percentages.

1.6 2.4 1.2 6.6 2.3 0.0 1.8 2.5 6.5 1.8
2.7 2.0 1.9 1.3 2.7 1.7 1.3 2.1 2.8 1.4
3.8 2.1 3.4 1.3 1.5 2.9 2.6 0.0 4.1 2.9
1.9 2.4 0.0 1.8 3.1 3.8 3.2 1.6 4.2 0.0
1.2 1.8 2.4

(a) Use a calculator with mean and standard deviation keys to find x and s. (Round your answers to two decimal places.)

x = %
s = %


(b) Compute a 90% confidence interval for the population mean μ of home run percentages for all professional baseball players. Hint: If you use the Student's t distribution table, be sure to use the closest d.f. that is smaller. (Round your answers to two decimal places.)

lower limit     %
upper limit     %


(c) Compute a 99% confidence interval for the population mean μ of home run percentages for all professional baseball players. (Round your answers to two decimal places.)

lower limit     %
upper limit     %

In: Statistics and Probability

$1M is available to invest in S or B. The percentage yield on each investment depends...

$1M is available to invest in S or B. The percentage yield on each investment depends on whether the econ has a good or bad year.

Econ has a Good year    Econ has a Bad year

Yield on S    22% of 1M 10% of 1M

   (i.e. $220,000)    ($100,000)

Yield on B 16% of 1M 14% of 1M

($160,000) ($140,000)

It is equally likely (50%) that the econ will have a good or bad year.

For $10,000, a firm can be hired to forecast the state of the econ. The firm's forecasts have the following probabilities:

p(Good forecast | Econ is good) = .8

p(GF | EIB) = .2

It is equally likely (50%) for EIG & EIB to occur

a) Calculate the following:

p(EIG | GF) =

p(EIB | GF) =

p(EIG | BF) =

p( EIB | BF) =

b) Draw a decision tree to determine to invest in S or B to maximize expected profits. Should the firm be hired?

c) What are the values of the EVSI and EVPI?

In: Math

An online bookstore predicts that the percentage of college students buying anthropology books online is not...

An online bookstore predicts that the percentage of college students buying anthropology books online is not equal to 45 %, on average. Several of the bookstore’s client universities would like to know if this is likely, so the online bookstore decides to do a hypothesis test at a 10% significance level. Data is collected from 11 universities providing the following information: H0: μ=45; Ha: μ≠45 x¯=51 σ=4 α=0.1 (significance level) The test statistic is z0=x¯−μ0σn√=51−45411√=4.97 The critical values are −z0.05=−1.64 and z0.05=1.64. Conclude whether to reject or not reject H0, and interpret the results. Based on this context and the null and alternative hypothesis, what type of hypothesis test should be used? Use the curve below to show your answer. Select the appropriate test by dragging the blue point to a right-, left- or two-tailed diagram. The shaded area represents the rejection region. Then, set the critical value(s) on the x-axis by moving the purple slider on the right. Provide your answer below:

In: Math

How does the percentage of voters who are renters (as opposed to owners) affect the incentives...

How does the percentage of voters who are renters (as opposed to owners) affect the incentives for politicians to propose rent controls? Does this incentive depend on the likelihood that renters are less likely to vote in local elections than are owners of apartments and houses? Why do you suppose renters are less likely to vote in local elections? Explain.

In: Economics

Use the percentage method to compute the federal income taxes to withhold from the wages or...

Use the percentage method to compute the federal income taxes to withhold from the wages or salaries of each employee. If an amount is zero, enter "0". If required, round your calculations and final answers to the nearest cent.

Click here to access the Table of Allowance Values.

Click here to access the Percentage Method Tables.


Employee
No.

Employee Name

Marital
Status
No. of Withholding
Allowances

Gross Wage
or Salary

Amount to Be
Withheld
1 Skymer, A. M 4 $ 1,575 weekly $
2 Wolfe, T. S 0 1,200 biweekly
3 Klein, G. S 5 12,600 quarterly
4 Carey, P. M 8 1,090 semimonthly
5 Wu, M. M 3 8,120 monthly

In: Accounting

As you've read in your text, the overall percentage of U.S. citizens participating in a stock...

As you've read in your text, the overall percentage of U.S. citizens participating in a stock market either through individual holdings or through financial intermediaries such as mutual funds has declined since the 2008 recession. Prior to 2008, a greater percentage of Americans held stock market investments than do in 2018. This is an interesting characteristic, given the following factors:

  1. Investing in the market through savings plans, 401k or 403b accounts, individual IRAs, or similar retirement plans has never been easier given the amount of information available to any individual. Individuals can invest small amounts such as $20 and benefit from dollar-cost averaging through automatic deposits and electronic transactions such as payroll deductions.
  2. While a vast majority of Americans will be dependent on Social Security as their primary source for retirement income, the message that relying solely on SS for retirement continues to be broadcast by media outlets such as the AARP.
  3. Since 2008, the markets have rebounded significantly from their 2008 lows.
  4. Basic principles of investing are easily located on the internet, from a variety of sources. For example, see the "Index Card" resource posted in Week 5, which is a short list of fundamental investing principles.

For this discussion post, you are to state a position and present an argument related to the above state of investing by U.S. citizens today. Why has the overall percentage of Americans invested in the market decreased in the last decade? And, subsequently, what can be done about this?    In your argument, which is to be supported by both textbook and outside research, delve into one or more of the primary concepts presented in this week's readings. These include the various stock market indexes, international markets, the role of the mutual fund industry, active versus passive investing, in addition to multiple other concepts.

In: Finance