The data provided give the gasoline mileage (in miles per gallon) based on the horsepower of a car's engine and the weight of the car (in pounds). Using the data provided, determine the VIF for each independent variable in the model. Is there reason to suspect the existence of collinearity?
Determine the VIF for each independent variable in the model.
MPG |
Horsepower |
Weight |
|
15.8 |
185 |
4,758 |
|
19.7 |
106 |
3,534 |
|
20.3 |
141 |
3,220 |
|
18.8 |
172 |
4,466 |
|
17.3 |
166 |
4,293 |
|
27.5 |
75 |
3,186 |
|
44.8 |
60 |
2,110 |
|
27.3 |
79 |
2,487 |
|
28.2 |
83 |
2,610 |
|
21.2 |
134 |
3,868 |
Round to three decimal places as needed.
In: Math
An experiment on memory was performed, in which 16 subjects were randomly assigned to one of two groups, called "Sentences" or "Intentional". Each subject was given a list of 50 words. Subjects in the "Sentences" group were told to form multiple sentences, each using at least two words from the list, and to keep forming sentences until all the words were used at least once. Subjects in the "Intentional" group were told to spend five minutes memorizing as many of the 50 words as possible. Subjects from both groups were then asked to write down as many words from their lists as they could recall. The data are in the table below. Number of words recalled "Sentences" group 29 30 35 33 32 29 33 34 "Intentional" group 31 36 36 32 34 33 30 33 Enter this data into JMP in "long form" (e.g. each column should be a variable and each row should be an observation). We are interested in determining if there is a significant difference in the average number of words recalled for subjects in the "sentences" group vs. subjects in the "intentional" group, using α = 0.05. Use JMP to answer the questions below, and round all answers to three decimal places.
standard error of (xsentences -
xintentional) =
test statistic: t =
p-value =
Report the 95% confidence interval JMP gives for
μsentences -
μintentional
Lower bound =
Upper bound =
From these results, our statistical conclusion should be:
(You have two attempts at this question.)
a.The means for "sentences" and "intentional" differ significantly, because the p-value is less than α and zero is inside the confidence interval
b. The means for "sentences" and "intentional" differ significantly, because the p-value is less than α and zero is outside the confidence interval
c. The means for "sentences" and "intentional" differ significantly, because the p-value is less than α and -1.25 is inside the confidence interval
d. The means for "sentences" and "intentional" differ significantly, because the p-value is less than α and -1.25 is outside the confidence interval
e.The means for "sentences" and "intentional" do not differ significantly, because the p-value is greater than α and zero is inside the confidence interval
f.The means for "sentences" and "intentional" do not differ significantly, because the p-value is greater than α and zero is outside the confidence interval
g.The means for "sentences" and "intentional" do not differ significantly, because the p-value is greater than α and -1.25 is inside the confidence interval
h. The means for "sentences" and "intentional" do not differ significantly, because the p-value is greater than α and -1.25 is outside the confidence interval
In: Math
In: Math
Suppose as part of a national study of economic competitiveness a marketing research firm randomly sampled 200 adults between the ages of 27 and 35 living in metropolitan Seattle and 180 adults between the ages of 27 and 35 living in metropolitan Minneapolis. Each adult selected in the sample was asked, among other things, whether they had a college degree. From the Seattle sample 66 adults answered yes and from the Minneapolis sample 63 adults answered yes when asked if they had a college degree. Based on the sample data, can we conclude that there is a difference between the population proportions of adults between the ages of 27 and 35 in the two cities with college degrees? Use a level of significance of 0.10 to conduct the appropriate hypothesis test.
Group of answer choices
A Since the test statistic, 1.8214, is greater than the critical value of 1.645, reject the null hypothesis and conclude that there is a higher proportion of Seattle adults that have a college degree
B Since the test statistic, 2.0112, is greater than the critical value of 1.645, reject the null hypothesis and conclude that there is a higher proportion of Seattle adults that have a college degree.
C Since the test statistic, 0.8921, is not greater than the critical value of 1.645, do not reject the null hypothesis and conclude that there is not a higher proportion of Seattle adults that have a college degree.
D Since the test statistic, -0.411, is not greater than the critical value of 1.645, do not reject the null hypothesis and conclude that there is not a higher proportion of Seattle adults that have a college degree.
In: Math
Do bonds reduce the overall risk of an investment portfolio? Let x be a random variable representing annual percent return for Vanguard Total Stock Index (all stocks). Let y be a random variable representing annual return for Vanguard Balanced Index (60% stock and 40% bond). For the past several years, we have the following data.
x: |
21 |
0 |
35 |
27 |
34 |
18 |
37 |
−17 |
−21 |
−20 |
y: |
16 |
−7 |
21 |
20 |
16 |
15 |
17 |
−1 |
−8 |
−8 |
(a) Compute Σx, Σx2, Σy, Σy2.
Σx | Σx2 | ||
Σy | Σy2 |
(b) Use the results of part (a) to compute the sample mean,
variance, and standard deviation for x and for y.
(Round your answers to two decimal places.)
x | y | |
x | ||
s2 | ||
s |
(c) Compute a 75% Chebyshev interval around the mean for x
values and also for y values. (Round your answers to two
decimal places.)
x | y | |
Lower Limit | ||
Upper Limit |
Use the intervals to compare the two funds.
75% of the returns for the balanced fund fall within a narrower range than those of the stock fund.75% of the returns for the stock fund fall within a narrower range than those of the balanced fund. 25% of the returns for the balanced fund fall within a narrower range than those of the stock fund.25% of the returns for the stock fund fall within a wider range than those of the balanced fund.
In: Math
You have been asked to conduct a study related to consumer loyalty toward three different retail formats (i.e., department stores, specialty stores, and off-price retailers). After gathering background information, you decide to focus your study on three research streams; retail service quality, consumer satisfaction, and consumer loyalty. The literature suggests that there are five dimensions of retail service quality; physical aspect, reliability, personal interaction, problem solving, and policy. According to the literature, consumer satisfaction is a unidimensional construct and consumer loyalty consists of two dimensions; word-of-mouth and behavioral intention. You want to learn whether or not influencing factors of consumer loyalty are different between these three types of retailers.
State the null hypothesis and the alternative hypothesis
What are the dependent and independent variables
What statistical test would you run in SPSS
In: Math
Dr. Mack Lemore, an expert in consumer behavior, wants to estimate the average amount of money that people spend in thrift shops. He takes a small sample of 8 individuals and asks them to report how much money they had in their pockets the last time they went shopping at a thrift store. Here are the data: 13.66, 41.35, 21.43, 10.49, 25.57, 37.04, 17.5, 27.07. Find the lower bound of a 98% confidence interval for the true mean amount of money individuals carry with them to thrift stores, to two decimal places. Take all calculations toward the final answer to three decimal places.
In: Math
In a small town, there are 5 high school districts. Each district includes 100 high school
students. In total, there are 500 high school students in the town including 240 male
students and 260 female students. Researchers would like to select a sample of 200
students.
(a) Explain how the sample can be obtained using random cluster sampling.
(b) Explain how the sample can be obtained using stratified random sampling.
(c) Explain how the sample can be obtained using systematic random sampling.
In: Math
A laptop assembly is subjected to a final functional test. Suppose that defects occur at random in these assemblies, and that defects occur according to a Poisson distribution with parameter λ= 0.03.
In: Math
In: Math
The diameter of a brand of tennis balls is approximately normally distributed, with a mean of 2.58 inches and a standard deviation of 0.03 inch. A random sample of 11 tennis balls is selected.
The probability is 69% that the sample mean will be between what two values symmetrically distributed around the population mean? (Round to two decimal places).
The lower bound is ___ inches, the upper bound is ___ inches.
In: Math
Scenario: Imagine that a psychologist working with veterans with post-traumatic stress disorder wants to compare the effectiveness of several therapies focused on reducing symptoms of anxiety. The psychologist randomly sampled 20 veterans who recently returned from combat and randomly assigned each of them to receive one of four interventions for 8 weeks. A survey was used to measure the participants’ anxiety at the end of the 8 weeks. Higher anxiety scores indicate more anxiety.
Use SPSS to compare the mean anxiety scores with a one-way ANOVA.
• Anxiety scores for 5 veterans who received behavioral therapy |
108 |
109 |
107 |
105 |
106 |
• Anxiety scores for 5 veterans who received cognitive therapy |
105 |
102 |
104 |
102 |
106 |
• Anxiety scores for 5 veterans who received biofeedback therapy |
101 |
102 |
105 |
100 |
101 |
• Anxiety scores for 5 veterans who received medication therapy |
101 |
104 |
103 |
105 |
103 |
In: Math
The ages of a random sample of people who attended a recent soccer match are as follows:
23 35 14 37 38 15 45
12 40 27 13 18 19 23
37 20 29 49 40 65 53
18 17 23 27 29 31 42
35 38 22 20 15 17 21
a. Find the mean age.
b. Find the standard deviation.
c. Find the coefficient of variation.
In: Math
An exam has 5 questions and each of them has 4
possible answers. A student gets 3 points
for each correct answer and loses 1 point for each wrong answer.
Consider a student who
answers all questions completely at random. Let X denote the number
of correct answers and
Y the number of points of this student at the end of the test. (A
negative score is possible).
(a) Compute the mean and the standard deviation of Y , µY and σY
.
(b) Compute P(µY − σY ≤ Y ≤ µY + σY ) and P(µY − 2σY ≤ Y ≤ µY + 2σY
).
(c) What is the probability that the student above gets a positive
score?
In: Math
Graphically speaking, what happens to the slope of an objective function if a coefficient in the objective function is changed?
In: Math