1. Create the printout for testing whether the mean low stock price of all NYSE stocks differs from $35 and attach it here. Answer the following questions regarding this printout:

1. In the words of the problem, give a practical conclusion for this test. Make sure to include your choice of α in this conclusion.
2. In the words of the problem, state what a Type I error would be.
3. Use your knowledge of p-values and the printout above to state what the p-value would have been if you were conducting a one-tailed test instead of the two-tailed test I asked for.

With the rise in fuel costs, the price unit cost of the majority of beef products have increased, you are interested in the cost of 700kg fillet. The price of a 700g fillet steak in dollars was taken from the menus of 30 restaurants. The prices are as follows:

148 , 95 , 150 , 125 , 75 , 185 , 105 , 165 , 139 , 185

205 , 126 , 144 , 95 , 151 , 310 ,110 , 99 , 180 , 146

70 , 148, 160 , 138 , 89 , 146 , 180 , 170 , 123 , 170

a. Calculate and interpret the mean, median and modal price of 700 fillet steak meal from the 30 menus of the samples restaurants.

b. Calculate the standard deviation, coefficient of variation,

c. Calculate the quartile deviation of prices

The business faculty of a public university recorded data on the number of students enrolled in the different study majors for the years 2018 and 2019. These data are useful for the faculty for their decision making process with regard to future planning. The data are stored in BUSSTUDYMAJOR worksheet in the .xls file attached.

1. Use an appropriate graphical technique or chart to display the percentage value of the number of enrolment of the different study major in 2018. Display the chart.

BUSSTUDYMAJOR worksheet details:

QUESTION 1

1. If Z is a standard normal random variable, then P(Z > 0) =  

   		0
   		1
   		0.4579
   		0.5

1 points   

QUESTION 2

1. Company A claims that 20% of people in Sydney prefer its product (Brand A). Company B disputes the 20% but has no idea whether a higher or lower proportion is appropriate.  Company B randomly samples 400 people and 88 of them prefer Company A's product (Brand A).
   Assuming a 5% significance level, which one of the following statements is correct?

   		This is a one-tailed test. Accept the null hypothesis because the test statistic value of 1.0 is less than the critical value of 1.96.
   		Do not reject the null hypothesis that Company A's claim is correct.
   		This is a two-tailed test. Reject the null hypothesis because the test statistic exceeds the critical value.
   		Reject the null hypothesis. This is a one-tail test with a test statistic value of 1.75 and a critical value of 1.645

1 points   

QUESTION 3

1. The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made.

   Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years.

   The calculated value (to three decimal places) of the test statistic is

1 points   

QUESTION 4

1. In a recent survey of 600 adults, 16.4% indicated that they had fallen asleep in front of the television in the past month.  Which of the following intervals represents a 98% confidence interval?

   		0.129 to 0.199
   		0.117 to 0.211
   		0.161 to 0.167
   		0.145 to 0.183

1 points   

QUESTION 5

1. In an upper-tail hypothesis test the calculated test statistic is z = 1.08. The p-value is closest to:

   		0.1401
   		0.2802
   		0.3431
   		0.3599

1 points   

QUESTION 6

1. The average amount of time a random sample of 25 teenagers spent on the internet per week was 9.5 hours with a standard deviation of 2.0 hours

   Assume that the distribution of the amount of time spent weekly on the internet by teenagers is normal.

   The upper limit (to three decimal places) of a 95% confidence interval for the average amount of time spent weekly on the internet by teenagers is

1 points   

QUESTION 7

1. To locate the rejection region:

   		the level of α must be specified.
   		the level of β must be specified.
   		both  α and β must be specified.
   		neither α nor β need be specified.

1 points   

QUESTION 8

1. A bank manager would like to determine whether the average monthly balance of credit card holders is equal to $750.

   An auditor selects a random sample of 100 accounts and finds that the average owed is $830.40 with a sample standard deviation of $236.50. This sample is used to perform an appropriate hypothesis test to test whether the average balance is not $750

   At a 5% level of significance the positive critical value of this hypothesis test is

1 points   

QUESTION 9

1. If a random sample of size n is drawn from a normal population, then the sampling distribution of the sample mean will be:

   		normal for all values of n.
   		normal only for n > 30.
   		approximately normal for all values of n.
   		approximately normal only for n > 30.

1 points   

QUESTION 10

1. The 99% confidence interval estimate of a population mean is to be calculated. A random sample of six observations from a normal population is to be used on which to base the estimate. If the population variance is unknown the tabulated numerical value that must be used to find the upper limit of the confidence interval is:

   		z = 2.576
   		t = 3.707
   		t = 4.032
   		z = 3.291

Type or paste question here

The business faculty of a public university recorded data on the number of students enrolled in the different study majors for the years 2018 and 2019. These data are useful for the faculty for their decision making process with regard to future planning. The data are stored in BUSSTUDYMAJOR worksheet in the .xls file attached.

1. Use an appropriate graphical technique or chart to compare the number of enrolment in 2018 and 2019 of the different study major. Display the chart.  

BUSSTUDYMAJOR worksheet details:

A car company is considering a new engine filter for its new hybrid automobile line. But it does not want to switch to the new brand unless there is evidence that the new filter can improve fuel economy for the vehicle (miles per gallon). The experimental design is set up so that each of the 10 cars drive the same course twice - once with the old filtration system and once with the new version. The data collected is shown below:

Conduct a hypothesis testing to determine whether the new filtration system is superior. Provide the p-value from your analysis.

Is the national crime rate really going down? Some sociologists say yes! They say that the reason for the decline in crime rates in the 1980s and 1990s is demographics. It seems that the population is aging, and older people commit fewer crimes. According to the FBI and the Justice Department, 70% of all arrests are of males aged 15 to 34 years†. Suppose you are a sociologist in Rock Springs, Wyoming, and a random sample of police files showed that of 39 arrests last month, 26 were of males aged 15 to 34 years. Use a 5% level of significance to test the claim that the population proportion of such arrests in Rock Springs is different from 70%.

(a) What is the level of significance?


State the null and alternate hypotheses.

H₀: p = 0.7; H₁: p > 0.7

H₀: p = 0.7; H₁: p ≠ 0.7    

H₀: p = 0 .7; H₁: p < 0.7

H₀: p ≠ 0.7; H₁: p = 0.7

H₀: p < 0 .7; H₁: p = 0.7

(b) What sampling distribution will you use?

The Student's t, since np > 5 and nq > 5.

The standard normal, since np < 5 and nq < 5.   

The standard normal, since np > 5 and nq > 5.

The Student's t, since np < 5 and nq < 5.

What is the value of the test statistic? (Round your answer to two decimal places.)


(c) Find the P-value of the test statistic. (Round your answer to four decimal places.)


Sketch the sampling distribution and show the area corresponding to the P-value.

(d) Based on your answers in parts (a) to (c), will you reject or fail to reject the null hypothesis? Are the data statistically significant at level α?

At the α = 0.05 level, we reject the null hypothesis and conclude the data are statistically significant.

At the α = 0.05 level, we reject the null hypothesis and conclude the data are not statistically significant.    

At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are statistically significant.

At the α = 0.05 level, we fail to reject the null hypothesis and conclude the data are not statistically significant.

(e) Interpret your conclusion in the context of the application.

There is sufficient evidence at the 0.05 level to conclude that the true proportion of arrests of males aged 15 to 34 in Rock Springs differs from 70%.

There is insufficient evidence at the 0.05 level to conclude that the true proportion of arrests of males aged 15 to 34 in Rock Springs differs from 70%.    

The owners of an e-business have been successful in selling fashion products but are now venturing into another domain. Knowing that the impact of advertising on profit cannot be overemphasized, they are interested in determining the right amount to allocate to advertising for the new business. Based on a monthly report from the fashion e-business, a regression analysis of monthly profit (in thousands of dollars) on advertising spending (in hundreds of dollars) produced the following results:

where yy = profit (in $1000s)
           xx = advertising spending (in $100s)

a. State the least-squares regression line for the data.
ŷ = ŷ =

++

xx

b. Interpret the value of the slope as it relates to this problem.

For every $1 increase in advertising spending, there is a $1.213 increase in profit.

For every $100 increase in advertising spending, there is a $1,213 increase in profit.

For every $100 increase in advertising spending, there is a $121.3 increase in profit.

For every $1,000 increase in advertising spending, there is a $121.3 increase in profit.

c. Compute and interpret the coefficient of determination.
R2=R2=

Round to 4 decimal places

d. Predict the monthly profit for a month when advertising is $2,300.

Round to the nearest cent

e. If the expected profit in a particular month is $43,448, about how much should be set aside for advertising that month?

Round to the nearest cent

Refer to the gasoline sales time series data in the given table.

A company is considering drilling oil wells. The probability of success for each well is 0.20. The cost of each well is $5 (in1000). Each well that is successful will be worth $60 (in 1000).

1) If the company drills 4 wells, the probability of at least one successful well is

2) If the company drills 40 wells, the approximate probability of at most one successful well is

3) The expected profit and the variance of profit in 4 drillings are

A class in probability theory consists of 3 men and 5 women. An exam is given, and the students are ranked according to their performance. Assuming that no two students obtain the same score, and all rankings are considered equally likely.

1.The probability that women receive the bottom 5 scores is

2.The probability that the top grade and the bottom grade are for men is

(Be sure to paste the R Console Output and code!!!) Using the following data and R, write a brief paragraph about whether the in-home treatment is equally effective as the out-of-home treatment for two separate groups. Here are the data. The outcome variable is level of anxiety after treatment on a scale from 1 to 10.

2) Describe what exploratory, descriptive, and causal research is and how they are related to one another. Provide an example of each type of research.

3) What are the four requirements for claiming causality? Do we meet these requirements in the following situations?

• Good user design led to Google’s Android becoming the market leader.

• When Rolex charges a higher price, this increases sales.

• More advertising causes greater sales.

A medIV. A medical trial into the effectiveness of a new medication was carried out. 120 females and 90 males took part in the trial. Out of those people, 50 females and 30 males responded positively to the medication. Given below is a contingency table with the given information filled in. Female Male Total Positive 50 30 Negative 70 60 Total a. What is the probability that a randomly selected person from the sample is a female? b. What is the probability that the medicine gives a positive result for males? c. What is the probability that a randomly selected person from the sample either a female or responded positively to the medication? d. What is the probability that a randomly selected person from the sample is a female given that she is responded positively to the medication? e. Was the medication's success independent of gender? Explain. ical trial into the