Consider the following regression output with Sunday circulation of newspapers as dependent variable and Daily circulation as independent variable. Both Sunday and Daily circulation and measured in thousands of copies.
Dependent Variable: Sunday |
||
Variable: |
Intercept |
Daily |
Coefficient |
24.763 |
1.351 |
Std. Error |
46.99 |
0.09 |
t Stat |
0.527 |
14.532 |
P-value |
0.602 |
0.000 |
Given the output above choose whether the following statement is TRUE or FALSE.
Question 1
This regression is bad because we are only 39.8% confident that the
intercept coefficient is not 0.
a: TRUE | |||||||||||||||
b: FALSE Question 2 ( it part 2 of the first
queestion)
|
In: Math
1. Quinnipiac University conducted a telephone survey with a randomly selected national sample of 1155 registered voters. The survey asked the respondents, “In general, how satisfied are you with the way things are going in the nation today?” (Quinnipiac University, February 7, 2017). Response categories were Very satisfied, Somewhat satisfied, Somewhat dissatisfied, Very dissatisfied, Unsure/No answer. a. What is the relevant population? b. What is the variable of interest? Is it qualitative or quantitative? c. What is the sample and sample size? d. What is the inference of interest to Gallup; that is, what are they trying to measure or learn about? e. What method of data collection is employed? f. How likely is the sample to be representative? g. Would it make more sense to use averages or percentages as a summary of the data for this question? h. Of the respondents, 24% said they felt somewhat satisfied. How many individuals provided this response?
In: Math
find the sample size needed to give a margin of error to estimate a proportion within plus minus 2% within 99% confidence within 95% confidence within 90% confidence assume no prior knowledge about the population proportion p
In: Math
Use R to complete the following questions. You should include your R code, output and plots in your answer.
1. Two methods of generating a standard normal random variable are:
a. Take the sum of 5 uniform (0,1) random numbers and scale to have mean 0 and standard deviation 1. (Use the properties of the uniform distribution to determine the required transformation).
b. Generate a standard uniform and then apply inverse cdf function to obtain a normal random variate (Hint: use qnorm).
For each method generate 10,000 random numbers and check the distribution using
a. Normal probability plot
b. Mean and standard deviation
c. The proportion of the data lying within the theoretical 2.5 and 97.5 percentiles and the 0.5 and 99.5 percentiles. (Hint: The ifelse function will be useful)
In: Math
These problems may be solved using Minitab. Copy and paste the appropriate Minitab output into a word-processed file. Add your explanations of the output near the Minitab output. DO NOT SIMPLY ATTACH PAGES OF OUTPUT AS AN APPENDIX.
Each problem should be able to fit on one or two pages, and each problem should include the following:
Design 1 |
Design 2 |
Design 3 |
Design 4 |
Design 5 |
12.2 |
12.2 |
10.0 |
10.2 |
11.0 |
12.4 |
13.4 |
11.2 |
7.9 |
12.5 |
11.9 |
12.4 |
8.9 |
9.1 |
11.7 |
11.7 |
11.0 |
11.2 |
11.2 |
10.8 |
11.7 |
12.4 |
10.2 |
10.1 |
10.0 |
12.0 |
13.1 |
10.6 |
6.6 |
9.8 |
11.8 |
11.5 |
10.4 |
8.1 |
10.3 |
11.5 |
11.6 |
9.2 |
10.0 |
9.3 |
13.9 |
13.3 |
10.8 |
8.7 |
11.1 |
13.2 |
12.7 |
11.5 |
8.4 |
12.9 |
In: Math
2. Lactation promotes a temporary loss of bone mass to provide adequate
amounts of calcium for milk production. Consider the data on total
body bone mineral content for a sample both during lactation (L) and
in the post weaning period (P).
1 . 2 3 4 5 6 7 8 9 10
L 1928 2549 2825 1924 1628 2175 2114 2621 1843 2541
P 2126 2885 2895 1942 1750 2184 2164 2626 2006 2627
Does the data suggest that true average total body bone mineral con-
tent during post weaning exceeds that during lactation by more than
25g? Use results from an output you obtained from the R software to
state and test the appropriate hypotheses with 95% confidence level(show
all details of R, either print our the R code and result or hand-write
R code and result ). State any assumptions required for the test to be
valid.
5. The following table summarizes the skin colours and position of 368
NBA players in 2014. Suppose that an NBA player is randomly selected
from that years player pool.
2
Guard positionForward Center Total
white 26 30 28 84
skin colour black 128 122 34 284
Total 154 152 62 368
(a) Find out where the variable "skin colour" is independent with the
variable "position" with
alpha = 0.05
(b) We only concern about the variable "position". The media claims
that the proportion of "Guard" is the same as the proportion of "For-
ward", which is twice as the proportion of "Center". Conduct a test to
find out whether the statement is valid with 90% confidence interval.
(hint: to test H0: P1= 0.4, P2 = 0.4, P3= 0.2)
6. Complete the following ANOVA table ( find the value of ?1, ?2, ?3, ?4,
?5) [5] and give the null hypothesis and the alternative hypothesis, [2]
give your conclusion based on the ANOVA table [2].
ANOVA table
Df SumSq Mean Sq F value P value
brands 3 39.757 ?1 ?5 5.399e-07
Error 36 ?2 ?3
Total ?4 . 68.128
7. Refer to the
Bulletin of Marine Science (April 2010)
study of teams
of shermen shing for the red apiny lobster in Baja Valifornia Sur,
Mexico. Two variables measured for each of 8 teams from the Punta
Abreojos shing cooperative were y=total catch of lobsters (in kilo-
grams) during the season and x=average percentage of traps allocated
per day to exploring areas of unknown catch (called search frequency)
total catch search frequency
2785 35
6535 21
6695 26
4891 29
4937 23
5727 17
7019 21
5735 20
(a) Graph the data in a scatterplot (using R). What type of trend, if any,
could be observed?
(b) Add the regression line to the plot (using R, either hand-write the R
code and plot the graph or print your R code and graph).
(c)Give the null and alternative hypothesis for testing whether total catch
is negatively linearly related to search frequency. Find the p-vale of the test
and give the appropriate conclusion of the test using alpha = 0.05
(d) what's the coefficient of correlation between total catch and search
frequency?
In: Math
What are the advantage and disadvantage of assuming quadratic utility functions in mean variance analysis?
In: Math
Construct a scatter plot. Find the equation of the regression line. Predict the value of y for each of the x-values. Use this resource: Regression Give an example of two variables that have a positive linear correlation.
Give an example of two variables that have a negative linear correlation.
Give an example of two variables that have no correlation.
Height and Weight: The height (in inches) and weights (in pounds) of eleven football players are shown in this table.
Height, x 62 63 66 68 70 72 73 74 74 75 75 Weight, y 195 190 250 220 250 255 260 275 280 295 300
x = 65 inches x = 69 inches x = 71 inches
In: Math
A random sample of 130 observations produced a mean of ?⎯⎯⎯=36.1x¯=36.1 from a population with a normal distribution and a standard deviation σ=4.87.
(a) Find a 95% confidence interval for μ
≤ μ ≤
(b) Find a 99% confidence interval for μ
≤ μ ≤
(c) Find a 90% confidence interval for μ
≤ μ ≤
In: Math
Given are five observations for two variables, x and y. x i 1 2 3 4 5 y i 4 7 6 11 13 Round your answers to two decimal places. a. Using the following equation: Estimate the standard deviation of ŷ* when x = 3. b. Using the following expression: Develop a 95% confidence interval for the expected value of y when x = 3. to c. Using the following equation: Estimate the standard deviation of an individual value of y when x = 3. d. Using the following expression: Develop a 95% prediction interval for y when x = 3. If your answer is negative, enter minus (-) sign. to
In: Math
The average number of words in a romance novel is 64,290 and the
standard deviation is 17,422. Assume the distribution is normal.
Let X be the number of words in a randomly selected romance novel.
Round all answers to 4 decimal places where possible.
a. What is the distribution of X? X ~ N(___,____)
b. Find the proportion of all novels that are between 57,321 and
71,259 words. _____
c. The 95th percentile for novels is ____ words. (Round to the
nearest word)
d. The middle 50% of romance novels have from ____words to_____
words. (Round to the nearest word)
In: Math
find the sample size needed to give with 99% confidence a margin of error of plus or minus 5% when estimating proportion within plus minus 4% within plus minus 1%
In: Math
The mean output of a certain type of amplifier is 496 watts with a variance of 144. If 40 amplifiers are sampled, what is the probability that the mean of the sample would differ from the population mean by less than 1.2 watts? Round your answer to four decimal places.
In: Math
The College Board wanted to test whether students graduating from private colleges and students graduating from public universities had different amounts of student loan debt. A sample of students from 146 private colleges across the country yielded an average loan debt of $29,972 with a standard deviation of $3,200. A sample of students from 225 public universities yielded an average loan debt of $28,762 with a standard deviation of $5,600. Conduct the test at the α=0.02α=0.02 level of significance.
In: Math
What is meant by an absolute effect in epidemiologic research?
Present at least one relevant example.
In: Math