When you develop a research project, you need to have a reliable and valid method of measurement in your study. Using your anticipated research proposal, how will you address the issues of reliability and validity? What concerns do you have over reliability and validity in your study and how will you overcome these concerns? Next, read two of your classmates’ posts and analyze how they addressed reliability and validity in their studies. Do you have any recommendations for improving reliability and validity?
In: Math
A regional automobile dealership sent out fliers to prospective customers indicating that they had already won one of three different prizes: an automobile valued at $20000, a $150 gas card, or a $5 shopping card. To claim his or her prize, a prospective customer needed to present the flier at the dealership's showroom. The fine print on the back of the flier listed the probabilities of winning. The chance of winning the car was 1 out of 31,433, the chance of winning the gas card was 1 out of 31,433 and the chance of winning the shopping card was 31,431 out of 31,433. Complete parts (a) through (d).
a. How many fliers do you think the automobile dealership sent out?
b. Using your answer to (a) and the probabilities listed on the flier, what is the expected value of the prize won by a prospective customer receiving a flier?
c.Using your answer to (a) and the probabilities listed on the flier, what is the standard deviation of the value of the prize won by a prospective customer receiving a flier?
d.Do you think this is an effective promotion? why or why not?
In: Math
1. Using the 'pulp' data from the faraway package in R, determine whether there are any differences between the operators. What is the nature of these differences? (Note; You must do multiple comparisons). Please use R or R studio code. Thanks!
In: Math
Case Problem - Regression
Are you going to hate your new job?
Getting a new job can be exciting and uplifting. But what if you discover that after a short time on the job, that you hate your new job? Is there any way to determine ahead of time whether you will love or hate your new job? According to the Wall Street Journal, there are a few things to look for in the interview that might help you to determine whether you will be happy on that job.
A study conducted by the University of Connecticut posed several questions to employees to ascertain their job satisfaction. Themes included: relationship with the supervisor, overall quality of the work environment, total weekly hours worked, and opportunity for advancement at the job. Nineteen employees were asked to rate their job satisfaction on a scale of 0-100, with 100 being perfectly satisfied. The results of the survey are as follows. Assume that the relationship with a supervisor is rated from 0-50, with 50 as excellent. Overall workplace quality rated from 0-100, with 100 representing an excellent environment and opportunities for advancement on a scale of 0-50 with 50 representing excellent opportunity.
Job Relationship Overall Quality Total Hrs. Opportunities
Satisfaction w/ Supervisor Work Environ Worked/wk Advancement
55 27 65 50 42
20 12 13 60 28
85 40 79 45 7
65 35 53 65 48
45 29 43 40 32
70 42 62 50 41
35 22 18 75 18
60 34 75 40 32
95 50 84 45 48
65 33 68 60 11
85 40 72 55 33
10 5 10 50 21
75 37 64 45 42
80 42 82 40 46
50 31 46 60 48
90 47 95 55 30
75 36 82 70 39
45 20 42 40 22
65 32 73 55 12
1. Develop a multiple regression model and analyze the data above related to job satisfaction. Use the four step analytical process to analyze the data. Test at the 0.05 level of significance and discuss in detail.
2. Of the variables above that are related to job satisfaction, which variables are stronger predictors of job satisfaction? Are other variables not mentioned here, potentially related to job satisfaction? Discuss in detail.
In: Math
A factorial experiment was designed to test for any significant differences in the time needed to perform English to foreign language translations with two computerized language translators. Because the type of language translated was also considered a significant factor, translations were made with both systems for three different languages: Spanish, French, and German. Use the following data for translation time in hours.
| Language | |||
| Spanish | French | German | |
| System 1 | 6 | 12 | 14 |
| 10 | 16 | 18 | |
| System 2 | 5 | 14 | 19 |
| 9 | 16 | 25 | |
Test for any significant differences due to language translator system (Factor A), type of language (Factor B), and interaction. Use a= .05.
Complete the following ANOVA table (to 2 decimals, if necessary). Round your p-value to 4 decimal places.
| Source of Variation | Sum of Squares | Degrees of Freedom | Mean Square | F | p-value |
| Factor A | |||||
| Factor B | |||||
| Interaction | |||||
| Error | |||||
| Total |
In: Math
A Saskatchewan farm machinery manufacturing company has developed a prototype of two machinery models (A and B). The manufacturer wishes to select one of these machines for further manufacturing. Also the manufacturer is under no obligation to select any of these 2 machines. The company has hired you to make a recommendation to the manufacturer not eh selection of the best alternative. In further discussion with the manufacturer you select the following attributes of the decision problem: a) manufacturers major motivation in selecting the best farm machinery in economic-improve the level of earnings for the company b)major uncertainty facing the selection process is future markets. Given above attributes, you decide to undertake a market survey, which resulted in 3 possible types of markets: Bouyant, steady state and Depressed. You also estimated the there are 3 types of markets prevail 50:20:30 percent, respectively, of the time in the future. You also estimated the net revenues of the company from sales of 2 types of machinery in thousands of dollars shown below:
| Pariculars | Bouyant | Steady State | Depressed Market |
| A | 2200 | 800 | 1000 |
| B | 3500 | 1500 | -1000 |
| Neither | 0 | 0 | 0 |
Using a decision three model, provide your recommendation to the farm machinery manufacturing company.
In: Math
The director of admissions at the University at the University of Maryland, University College is concerned about the high cost of textbooks for the students each semester. A sample of 25 students enrolled in the university indicates that x(bar) = $315.40 and s = $43.20.
A mean that is not in a confidence interval is rejected by the confidence interval, and we say the evidence against the mean is significant. At the 0.10 level of significance, is there evidence against mean $300?
In: Math
A magazine reported that at the top 50 business schools in a region, students studied an average of 17.8 hours. Set up a hypothesis test to try to prove that the mean number of hours studied at your school is different from the reported 17.8 hour benchmark. Complete parts (a) through (c) below.
a. State the null and alternative hypotheses. Choose the correct answer below.
A. Upper H 0: alpha not equals 17.8 Upper H 1: alpha equals 17.8
B. Upper H 0: beta not equals 17.8 Upper H 1: beta equals 17.8
C. Upper H 0: muequals17.8 Upper H 1: Upper X overbarnot equals17.8
D. Upper H 0: Upper X overbarequals17.8 Upper H 1: Upper X overbarnot equals17.8
E. Upper H 0: alpha equals 17.8 Upper H 1: beta not equals 17.8
F. Upper H 0: munot equals 17.8 Upper H 1: Upper X overbar equals17.8
G. Upper H 0: alphaequals17.8 Upper H 1: alphanot equals17.8
H. Upper H 0: muequals17.8 Upper H 1: munot equals17.8
I. Upper H 0: Upper X overbarnot equals17.8 Upper H 1: Upper X overbarequals17.8
J. Upper H 0: alphanot equals17.8 Upper H 1: betaequals17.8
K. Upper H 0: munot equals17.8 Upper H 1: muequals17.8
L. Upper H 0: betaequals17.8 Upper H 1: betanot equals17.8
b. What is a Type I error for your test?
A. Concluding that the mean number of hours studied at your school is different from the reported 17.8 hour benchmark when in fact it is different
B. Concluding that the mean number of hours studied at your school is not different from the reported 17.8 hour benchmark when in fact it is different
C. Concluding that the mean number of hours studied at your school is different from the reported 17.8 hour benchmark when in fact it is not different
c. What is a Type II error for your test?
A. Concluding that the mean number of hours studied at your school is not different from the reported 17.8 hour benchmark when in fact it is different
B. Concluding that the mean number of hours studied at your school is different from the reported 17.8 hour benchmark when in fact it is different
C. Concluding that the mean number of hours studied at your school is different from the reported 17.8 hour benchmark when in fact it is not different
In: Math
Describe the key difference between the separation of between treatment variability for the one-factor independent measures ANOVA and the two-factor independent measures factorial ANOVA.
In: Math
Assume that the heights of men are normally distributed with a mean of 69.0 inches and a standard deviation of 2.8 inches. If 1 man is randomly selected, find the probability that he has a height between 68 and 70 inches.
In: Math
Let X denote the time in minutes (rounded to the nearest ½
minute) for blood samples to be taken from patients in UrgentCare
clinic near Mountainside, NJ. A random survey of 200 patients
revealed the following frequency distribution in minutes.
X = x (mins)
0 0.5 1.0 1.5 2.0 2.5
Freq (# of patients)
20 38 62 44 14 22
Determine the following:
a) P (X < 2.0)
b) P (0.75 < X ≤ 1.5)
c) P (X ≥ 2.0)
d) P (X = 1.5)
e) Mean and standard deviation of the random variable X
f) Interpretation of mean of random variable X.
g) Draw a probability histogram (pdf) for the random variable X and
locate the mean (draw a vertical dash line to indicate the mean) in
a graph. Mark the x-axis and y-axis and indicate the variables and
the scales appropriately.
h) Construct the c.d.f. for the random variable X in a graph
formats. Mark the x-axis and y-axis and indicate the variable and
the scale appropriately.
In: Math
The credit department of Lion’s Department Store in Anaheim, California, reported that 26% of their sales are cash, 27% are paid with a credit card, and 47% with a debit card. Twenty percent of the cash purchases, 86% of the credit card purchases, and 61% of the debit card purchases are for more than $50. Ms. Tina Stevens just purchased a new dress that cost $120. What is the probability that she paid cash? (Round your answer to 3 decimal places.)
A) Probability:
In: Math
Nike claims that the number of miles a jogger can get a on a pair of Nike’s running shoes is higher than 1000. Moreover, Nike also claims that their shoes outperform Adidas shoes by more than 15 miles. We have samples of 150 joggers using Nike shoes and 170 using Adidas shoes. The sample average of miles they got are 1015 for Nike and 995 for Adidas. The sample standard deviations are 100 for Nike and 50 for Adidas.
a.) At a 5% level of significance, is there statistical evidence showing that Nike shoes get more than 1000 miles?
b.) Obtain the p-value for the previous test. What does it mean?
c.) At a 5% level of significance, is there statistical evidence showing that Nike shoes outperform Adidas shoes?
d.) Obtain the p-value for the previous test. Interpret.
In: Math
A survey of 1000 adults from a certain region asked, "Do you enjoy shopping for clothing for yourself?" The results indicated that 59% of the females enjoyed shopping for clothing for themselves as compared to 51% of the males. The sample sizes of males and females were not provided. Suppose that of 600 females, 354 said that they enjoyed shopping for clothing for themselves while of 400 males, 204 said that they enjoyed shopping for clothing for themselves. Complete parts (a) through (d) below.
a. Is there evidence of a difference between males and females in the proportion who enjoy shopping for clothing for themselves at the 0.1 level of significance? State the null and alternative hypotheses, where pi 1 is the population proportion of females that enjoy shopping for themselves and pi 2 is the population proportion of males that enjoy shopping for themselves.
Determine the value of the test statistic.
Determine the critical value(s) for this test of hypothesis.
The critical value(s) is (are) nothing
find the p value
Construct and interpret a 90% confidence interval estimate for the difference between the proportion of males and females who enjoy shopping for clothing for themselves.
What are the answers to (a) through (c) if 212 males enjoyed shopping for clothing for themselves?
Is there evidence of a difference between males and females in the proportion who enjoy shopping for clothing for themselves at the 0.1 level of significance? State the null and alternative hypotheses, where pi 1π1 is the population proportion of females that enjoy shopping for themselves and pi 2π2 is the population proportion of males that enjoy shopping for themselves.
Determine the value of the test statistic.
Determine the critical value(s) for this test of hypothesis.
The critical value(s) is (are)
Find the p-value and interpret its meaning.
Construct and interpret a 90% confidence interval estimate for the difference between the proportion of males and females who enjoy shopping for clothing for themselves.
In: Math
Interpret these correlation coefficients:
•r = -0.84 between total mileage and car resale value
•r = 0.03 between anxiety level and college GPA
•r = 0.56 between age of schoolchildren and reading comprehension
In: Math