Questions
Consider the quarterly electricity production for years 1-4: Year 1 2 3 4 Q1 99 120...

Consider the quarterly electricity production for years 1-4: Year 1 2 3 4 Q1 99 120 139 160 Q2 88 108 127 148 Q3 93 111 131 150 Q4 111 130 152 170 (a) Estimate the trend using a centered moving average. (b) Using a classical additive decomposition, calculate the seasonal component. (c) Explain how you handled the end points. Note: Explain all the steps and computations in your own words and it should be typed on Microsoft word .

In: Math

Locate the results of a recent survey that show at least two variables in a newspaper,...

Locate the results of a recent survey that show at least two variables in a newspaper, magazine, or internet article. Outline the survey data so that your peers can understand the variables and results. Then identify at least one key statistical inference formula involving two of more parameters that you could use to evaluate the data. Provide a brief explanation of why you selected the formula you did and why it matters. Also, explain what the formula is and where it is in the textbook and clearly define your parameters. Do not use regression or correlation examples since we will cover them during the next module.

Be sure to support your statements with logic and argument, citing any sources referenced.

In: Math

As a shift manager at a local fast food place, you are responsible for ensuring quality...

As a shift manager at a local fast food place, you are responsible for ensuring quality control. You do not want to weigh all the frozen hamburger patties that get delivered by your supplier to make sure they weigh four ounces on average, so you choose 25 patties at random. You calculate that the sample mean weight of patties is 3.4 ounces and the standard deviation of the weight of hamburger patties to be 0.5 ounces.

(a) Test the hypothesis that the population mean weight of patties is equal to 4 ounces.

(b) You are particularly concerned about the population weight being under 4 ounces, is there any reason for concern? Explain using the concept of a confidence interval.

In: Math

What is the difference between a Paired t-test and a Pooled t-test?

What is the difference between a Paired t-test and a Pooled t-test?

In: Math

Let x be a random variable that represents the pH of arterial plasma (i.e., acidity of...

Let x be a random variable that represents the pH of arterial plasma (i.e., acidity of the blood). For healthy adults, the mean of the x distribution is μ = 7.4.† A new drug for arthritis has been developed. However, it is thought that this drug may change blood pH. A random sample of 41 patients with arthritis took the drug for 3 months. Blood tests showed that x = 8.4 with sample standard deviation s = 3.0. Use a 5% level of significance to test the claim that the drug has changed (either way) the mean pH level of the blood.

(a) What is the level of significance?


State the null and alternate hypotheses.

H0: μ > 7.4; H1: μ = 7.4

H0: μ = 7.4; H1: μ > 7.4    

H0: μ = 7.4; H1: μ ≠ 7.4

H0: μ = 7.4; H1: μ < 7.4

H0: μ ≠ 7.4; H1: μ = 7.4


(b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution.

The Student's t, since the sample size is large and σ is unknown.

The standard normal, since the sample size is large and σ is unknown.    

The Student's t, since the sample size is large and σ is known.

The standard normal, since the sample size is large and σ is known.


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


(c) Estimate the P-value.

P-value > 0.250

0.100 < P-value < 0.250    

0.050 < P-value < 0.100

0.010 < P-value < 0.050

P-value < 0.010


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 drug has changed the mean pH level of the blood.

There is insufficient evidence at the 0.05 level to conclude that the drug has changed the mean pH level of the blood.    

In: Math

Give a scientific method, procedure or ways to determine the statistics in order to investigate, or...

Give a scientific method, procedure or ways to determine the statistics in order to investigate, or analyze the characteristic and behaviour of electric-powered two and three wheelers in terms of the factors such as safety, travel time, accessibility, cost for a user. I need help for a research class on determining the characteristic and behaviour of people.

In: Math

) The U.S. Census Bureau computes quarterly vacancy and homeownership rates by state and metropolitan statistical...

) The U.S. Census Bureau computes quarterly vacancy and homeownership rates by state and metropolitan statistical areas. The following data are the rental vacancy rates in percentage (%) grouped by region for the first quarter of 2019 using a sample of 4 statistical metropolitan areas.

Vacancy rates (%)

Region Northeast South West
1 6 12 8

2 5 9 10

3 9 11 8

4 4 8 6

Sample Mean Sample   6 10 8

Variance 4.7 3.3 2.7

a.(10pt) Perform an ANOVA test to find if there are vacancy rates differences among the regions. Allow 1% error on your test.

b. (5pt) Do you think that the mean vacancy rate is the same for these regions? Why?

In: Math

We consider 7 bags each containing 6 balls. Each ball is numbered from 1 to 6....

We consider 7 bags each containing 6 balls. Each ball is numbered from 1 to 6. The first 6 bags contain 6 balls where all numbers from 1 to 6 are present. The 7th bag contains 6 balls that all have the same number equal to 6. You take a bag randomly. You shoot a ball and put it back in its bag. You shoot another ball and you put it back in his bag and you observe that the two balls have the number 6. What is the probability of choosing the 7th bag?

On considère 7 sacs contenant chacun 6 balles. Chaque balle est numérotée de 1 à 6. Les 6 premiers sacs contiennent 6 balles où tous les numéros de 1 à 6 sont présents. Le 7-ième sac contient 6 balles qui ont toutes le même numéro égal à 6. Vous prenez un sac au hasard. Vous tirez une balle et vous la replacez dans son sac. Vous tirez une autre balle et vous la replacez dans son sac et vous observez que les deux balles ont le numéro 6. Quelle est la probabilité de choisir le 7-ième sac ?

In: Math

Jobs and productivity! How do retail stores rate? One way to answer this question is to...

Jobs and productivity! How do retail stores rate? One way to answer this question is to examine annual profits per employee. The following data give annual profits per employee (in units of 1 thousand dollars per employee) for companies in retail sales. Assume σ ≈ 3.9 thousand dollars.

3.6

6.6

3.5

8.9

8.4

5.7

8.1

6.5

2.6

2.9

8.1

−1.9

11.9

8.2

6.4

4.7

5.5

4.8

3.0

4.3

−6.0

1.5

2.9

4.8

−1.7

9.4

5.5

5.8

4.7

6.2

15.0

4.1

3.7

5.1

4.2

(a) Use a calculator or appropriate computer software to find x for the preceding data. (Round your answer to two decimal places.)
thousand dollars per employee

(b) Let us say that the preceding data are representative of the entire sector of retail sales companies. Find an 80% confidence interval for μ, the average annual profit per employee for retail sales. (Round your answers to two decimal places.)

lower limit     thousand dollars
upper limit     thousand dollars


(c) Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores.No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


(d) Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores.No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


(e) Find an 95% confidence interval for μ, the average annual profit per employee for retail sales. (Round your answers to two decimal places.)

lower limit     thousand dollars
upper limit     thousand dollars


Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores.No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.    


Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b).

Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores.No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores.  

In: Math

This is for Predictive Analytics. 1. Read the iris data set into a data frame. 2....

This is for Predictive Analytics.

1. Read the iris data set into a data frame.

2. Print the first few lines of the iris dataset.

3. Output all the entries with Sepal Length > 5.

4. Plot a box plot of Petal Length with a color of your choice.

5. Plot a histogram of Sepal Width.

6. Plot a scatter plot showing the relationship between Petal Length and Petal Width.

7. Find the mean of Sepal Length by species. Hint: You could use the tapply function. Other methods are also acceptable.

8. Use the subset function to extract only rows where the species is "versicolor."

9. Install the dplyr package and load it on your console.

10. Use a function in the dplyr package to show only rows with Sepal Length <6 belonging to species "virginica."

Submit all the code and subsequent output as a word file

In: Math

Q1. An advertising company collected information from 10 Hollywood Movies, including the number of the first...

Q1. An advertising company collected information from 10 Hollywood Movies, including the number of the first year box office reciepts ad the total promotional costs for each movies. They wish to study the relationship between promotion cost and the box office reciepts.

First year box office reciepts (millions) 85.1 106.3 50.2 130.6 54.8 30.3 79.4 91.0 135.4 89.3

Total promotional costs (millions) 5.10 5.80 2.10 8.40 2.90 1.20 3.70 7.60 7.70 4.50

a. If we would like to use the promotion cost to predict the box office reciepts, could you implement a simple regression model? Please use the matrix approach to estimate the reregression coefficients. Report your residual vector e, SSTO, SSR,SSE.

b. check the model assumption of residual assumptions. List all the assumptions made here and use graphs or tests to evaluate at least two of them. Report your R code/ output and your conclusions.

In: Math

The service time in minutes from admit to discharge for ten patients seeking care in a...

  1. The service time in minutes from admit to discharge for ten patients seeking care in a hospital emergency department are 21, 136, 185, 156, 3, 16, 48, 28, 100, and 12.
    1. Use Minitab to construct a normal probability plot, an exponential probability plot, and a Weibull probability plot for these dat
    2. Do any of these distributions seem to be a reasonable probability model for the data? Explain your answer.

In: Math

The number of incorrectly transferred calls made per month is listed below for a sample of...

The number of incorrectly transferred calls made per month is listed below for a sample of 8 different months:
13 28 39 19 43 28 38 49
2.1 Calculate the mean number of incorrectly transferred calls made per month. Contextually interpret your answer. (3)
2.2 Calculate the median number of incorrectly transferred calls made per month. Contextually Interpret your answer. (3)

2.3 State the modal number of incorrectly transferred calls made per month. Contextually interpret your answer. (2)
2.4 Calculate the standard deviation for the number of incorrectly transferred calls made. (4)
2.5 Calculate Pearson’s median skewness coefficient for the number of incorrectly transferred calls made. Contextually interpret your answer. (3)
2.6 Which measure of central location would you use in your reporting – the mean, median or mode? Motivate your answer. (2)

In: Math

2. A University has completed an internal survey on its department achievements. The key question in...

2. A University has completed an internal survey on its department achievements. The key question in the survey is whether the professors think the new on-line system is effective. The following is the output of a statistical analysis of the data:
Is online system effective
Purpose
No
Yes
Assignments
30
35
Labs and hand on activities
25
40
Exams
20
45
Based on this output, can the president conclude that the opinion of the professors on whether the recently launched on-line system is effective is dependent on which region they belong to? Use a chi square test and a level of significance of 0.05.​
answer in word only pls

In: Math

A scientist has read that the mean birth weight μ of babies born at full term...

A scientist has read that the mean birth weight μ of babies born at full term is 7.3 pounds. The scientist, believing that the mean birth weight of babies born at full term is less than this value, plans to perform a statistical test. She selects a random sample of 50 birth weights of babies born at full term. Suppose that the population of birth weights of babies born at full term has a standard deviation of 1.7 pounds and that the scientist performs her hypothesis test using the 0.01 level of significance.

Based on this information, answer the questions below. Carry your intermediate computations to at least four decimal places, and round your responses as indicated.

(If necessary, consult a list of formulas.)

What are the null and alternative hypotheses that the scientist should use for the test?

H0:μ is

less than, less than or equal to, greater than, greater than or equal to, not equal to, equal to 7.3, 50, 1.7, 6.50

H1:μ is

less than, less than or equal to, greater than, greater than or equal to, not equal to, equal to 7.3, 50, 1.7, 6.50
Assuming that the actual value of µ is 6.50 pounds, what is the probability that the scientist rejects the null hypothesis? Round your response to at least two decimal places.
What is the probability that the scientist rejects the null hypothesis when, in fact, it is true? Round your response to at least two decimal places.
Suppose that the scientist decides to perform another statistical test using the same population, the same null and alternative hypotheses, and the same sample size, but for this second test the scientist uses a significance level of 0.05 instead of a significance level of 0.01. Assuming that the actual value of µ is 6.50 pounds, how does the probability that the scientist commits a Type II error in this second test compare to the probability that the scientist commits a Type II error in the original test? The probability of committing a Type II error in the second test is greater
The probability of committing a Type II error in the second test is less
The probabilities of committing a Type II error are equal

In: Math