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 4 percentage points with 99​% confidence if

he uses a previous estimate of 38%?

​(b) He does not use any prior​ estimates?

15% of all Americans suffer from sleep apnea. A researcher suspects that a higher percentage of those who live in the inner city have sleep apnea. Of the 315 people from the inner city surveyed, 63 of them suffered from sleep apnea. What can be concluded at the level of significance of αα = 0.01? Round numerical answers to 3 decimal places

1. For this study, we should use Select an answer z-test for a population proportion t-test for a population mean
2. The null and alternative hypotheses would be:
   Ho: ? p μ  Select an answer < > = ≠   (please enter a decimal)   
   H₁: ? μ p  Select an answer > ≠ = <   (Please enter a decimal)

3. The test statistic ? z t  =  (please show your answer to 3 decimal places.)
4. The p-value =  (Please show your answer to 4 decimal places.)
5. The p-value is ? ≤ >  αα
6. Based on this, we should Select an answer accept fail to reject reject  the null hypothesis.
7. Thus, the final conclusion is that ...
   • The data suggest the population proportion is not significantly larger than 15% at αα = 0.01, so there is not sufficient evidence to conclude that the population proportion of inner city residents who have sleep apnea is larger than 15%.
   • The data suggest the population proportion is not significantly larger than 15% at αα = 0.01, so there is sufficient evidence to conclude that the population proportion of inner city residents who have sleep apnea is equal to 15%.
   • The data suggest the populaton proportion is significantly larger than 15% at αα = 0.01, so there is sufficient evidence to conclude that the population proportion of inner city residents who have sleep apnea is larger than 15%
8. Interpret the p-value in the context of the study.
   • If the sample proportion of inner city residents who have sleep apnea is 20% and if another 315 inner city residents are surveyed then there would be a 0.65% chance of concluding that more than 15% of all inner city residents have sleep apnea.
   • There is a 0.65% chance that more than 15% of all inner city residents have sleep apnea.
   • If the population proportion of inner city residents who have sleep apnea is 15% and if another 315 inner city residents are surveyed then there would be a 0.65% chance that more than 20% of the 315 inner city residents surveyed have sleep apnea.
   • There is a 0.65% chance of a Type I error.
9. Interpret the level of significance in the context of the study.
   • There is a 1% chance that aliens have secretly taken over the earth and have cleverly disguised themselves as the presidents of each of the countries on earth.
   • If the population proportion of inner city residents who have sleep apnea is larger than 15% and if another 315 inner city residents are surveyed then there would be a 1% chance that we would end up falsely concluding that the proportion of all inner city residents who have sleep apnea is equal to 15%.
   • There is a 1% chance that the proportion of all inner city residents who have sleep apnea is larger than 15%.
   • If the population proportion of inner city residents who have sleep apnea is 15% and if another 315 inner city residents are surveyed then there would be a 1% chance that we would end up falsely concluding that the proportion of all inner city residents who have sleep apnea is larger than 15%.

Revenue Recognition - Percentage of Completion - Project Instructions, Spring 2018

One of your clients is a large regional construction company. The company has many long-term projects in the works. The spreadsheet you are given contains some information about these jobs. Some of the jobs began last year and continue into the current year, so they exist on both tabs. The projects are in various phases of construction; some of which were completed during the current year.

You've been asked by your firm to analyze the data and prepare the following:

1) Complete the revenue recognition process by adding the necessary calculations into the blank columns F-J and L-M on the Current Year and Prior Year tabs and populate the data for all rows. It is expected that you look back at the text for definitions and to remind yourself of the percentage of completion method prior to asking questions.

Current year:

Prior Yr:

A recent study about the blood types distribution reported that the percentage of B+ blood type holders in KSA is approximately 19.7%. A call for donation for B+ blood is released at University ofJeddah. What is the probability that the first donor with B+ blood type will be the 7th applicant?

explain line by line what it does

Description: This function applies discount percentage on an item

price unless the item price is less than the whole sale

price. For example, a product at $10 with a wholesale price of $5 and a discount

of 10% returns $9.

function applyDiscount(productPrice : Double,

       wholesalePrice : Double,

       discount : Double)

Return Double

Create variable discountedPrice as double

discountedPrice = productPrice * (1–discount)

if (discountedPrice < wholesalePrice)

     discountedPrice = wholesalePrice

end if

return discountedPrice

End function

Let x be a random variable representing percentage change in neighborhood population in the past few years, and let y be a random variable representing crime rate (crimes per 1000 population). A random sample of six Denver neighborhoods gave the following information.

In this setting we have Σx = 70, Σy = 586, Σx² = 1136, Σy² = 71,796, and Σxy = 8844.

(a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to four decimal places.)

(b) Draw a scatter diagram displaying the data. Graph the least-squares line on your scatter diagram. Be sure to plot the point (x, y).

(c) Find the sample correlation coefficient r and the coefficient of determination. (Round your answers to three decimal places.)

What percentage of variation in y is explained by the least-squares model? (Round your answer to one decimal place.)
%

(d) Test the claim that the population correlation coefficient ρ is not zero at the 10% level of significance. (Round your test statistic to three decimal places and your P-value to four decimal places.)

Conclusion

Reject the null hypothesis, there is sufficient evidence that ρ differs from 0.Reject the null hypothesis, there is insufficient evidence that ρ differs from 0.    Fail to reject the null hypothesis, there is sufficient evidence that ρ differs from 0.Fail to reject the null hypothesis, there is insufficient evidence that ρ differs from 0.

(e) For a neighborhood with x = 19% change in population in the past few years, predict the change in the crime rate (per 1000 residents). (Round your answer to one decimal place.)
crimes per 1000 residents

(f) Find S_e. (Round your answer to three decimal places.)
S_e =

(g) Find a 95% confidence interval for the change in crime rate when the percentage change in population is x = 19%. (Round your answers to one decimal place.)

(h) Test the claim that the slope β of the population least-squares line is not zero at the 10% level of significance. (Round your test statistic to three decimal places and your P-value to four decimal places.)

Conclusion

Reject the null hypothesis, there is sufficient evidence that β differs from 0.Reject the null hypothesis, there is insufficient evidence that β differs from 0.    Fail to reject the null hypothesis, there is sufficient evidence that β differs from 0.Fail to reject the null hypothesis, there is insufficient evidence that β differs from 0.

(i) Find a 95% confidence interval for β and interpret its meaning. (Round your answers to three decimal places.)

Interpretation

For every percentage point increase in population, the crime rate per 1,000 increases by an amount that falls within the confidence interval.

For every percentage point increase in population, the crime rate per 1,000 increases by an amount that falls outside the confidence interval.  

  For every percentage point decrease in population, the crime rate per 1,000 increases by an amount that falls within the confidence interval.

For every percentage point decrease in population, the crime rate per 1,000 increases by an amount that falls outside the confidence interval.

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote. Suppose that 686 employed persons and 669 unemployed persons are independently and randomly selected, and that 438 of the employed persons and 361 of the unemployed persons have registered to vote. Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote? Use a significance level of α=0.01 for the test.

State the null and alternative hypotheses for the test.

Find the values of the two sample proportions, pˆ1and pˆ2. Round your answers to three decimal places.

Compute the weighted estimate of p, ‾p. Round your answer to three decimal places.

Compute the value of the test statistic. Round your answer to two decimal places.

Determine the decision rule for rejecting the null hypothesis H₀. Round the numerical portion of your answer to three decimal places.

Make the decision for the hypothesis test.

1.Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n = 6 professional basketball players gave the following information.

x

86

70

80

76

70

67

y

57

43

46

50

50

41

Given that Se ≈ 4.075, a ≈ 16.319, b ≈ 0.435, and x bar≈ 74.833 , ∑x = 449, ∑y = 287, ∑x2 = 33,861, and ∑y2 = 13,895, find a 99% confidence interval for y when x = 72.

Select one:

a. between 25.3 and 66.8

b. between 25.6 and 66.6

c. between 25.8 and 66.3

d. between 27.0 and 65.1

e. between 24.9 and 67.2

2.Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n = 6 professional basketball players gave the following information.

x

65

80

68

64

69

71

y

43

49

51

47

42

52

Given that Se ≈ 4.306, a ≈ 17.085, b ≈ 0.417, and x bar≈ 69.5 , ∑x = 417, ∑y = 284, ∑x2 = 29,147, and ∑y2 = 13,528, find a 98% confidence interval for y around 53.4 when x = 87.

Select one:

a. between 26.4 and 77.3

b. between 25.1 and 78.6

c. between 24.6 and 79.1

d. between 21.3 and 82.5

e. between 23.8 and 79.9

3.Let x be a random variable that represents the percentage of successful free throws a professional basketball player makes in a season. Let y be a random variable that represents the percentage of successful field goals a professional basketball player makes in a season. A random sample of n = 6 professional basketball players gave the following information.

x

81

65

78

87

70

81

y

46

48

54

51

44

51

Given that Se ≈ 3.668, a ≈ 16.331, b ≈ 0.436, and x bar≈ 77 , use a 5% level of significance to find the P-Value for the test that claims β is greater than zero.

Select one:

a. 0.1 <  P-Value < 0.2

b. 0.005 <  P-Value < 0.01

c. P-Value < 0.005

d. 0.2 <  P-Value < 0.25

e. P-Value > 0.25

SCENARIO 12-7

Data on the percentage of 200 hotels in each of the three large cities across the world on whether minibar charges are correctly posted at checkout are given below.

At the 0.05 level of significance, you want to know if there is evidence of a difference in the proportion of hotels that correctly post minibar charges among the three cities.


Referring to Scenario 12-7, the expected cell frequency for the Hong Kong/Yes cell is ________.

The U.S. Census Bureau conducts annual surveys to obtain information on the percentage of the voting-age population that is registered to vote. Suppose that 608 employed persons and 719 unemployed persons are independently and randomly selected, and that 318 of the employed persons and 269 of the unemployed persons have registered to vote. Can we conclude that the percentage of employed workers ( p1 ), who have registered to vote, exceeds the percentage of unemployed workers ( p2 ), who have registered to vote? Use a significance level of α=0.01 for the test.

Step 1 of 6: State the null and alternative hypotheses for the test.

Step 2 of 6: Find the values of the two sample proportions, pˆ1p^1 and pˆ2p^2. Round your answers to three decimal places.

Step 3 of 6: Compute the weighted estimate of p, p‾p‾. Round your answer to three decimal places.

Step 4 of 6: Compute the value of the test statistic. Round your answer to two decimal places.

Step 5 of 6: Determine the decision rule for rejecting the null hypothesis H0H0. Round the numerical portion of your answer to two decimal places.

Step 6 of 6: Make the decision for the hypothesis test.