In: Math
ath & Music (Raw Data, Software
Required):
There is a lot of interest in the relationship between studying
music and studying math. We will look at some sample data that
investigates this relationship. Below are the Math SAT scores from
8 students who studied music through high school and 11 students
who did not. Test the claim that students who study music in high
school have a higher average Math SAT score than those who do not.
Test this claim at the 0.05 significance level.
| Studied Music | No Music | |
| count | Math SAT Scores (x1) | Math SAT Scores (x2) |
| 1 | 516 | 480 |
| 2 | 571 | 535 |
| 3 | 589 | 553 |
| 4 | 588 | 537 |
| 5 | 521 | 480 |
| 6 | 564 | 513 |
| 7 | 531 | 495 |
| 8 | 597 | 556 |
| 9 | 554 | |
| 10 | 493 | |
| 11 | 557 |
In: Math
Construct a truth table for the statement [q∨(~r∧p)]→~p.
Complete the truth table below by filling in the blanks. (T or F)
| p | q | r | ~r | ~r∧p | q∨(~r∧p) | ~p | [q∨(~r∧p)]→~p |
| T | T | T | |||||
| T | T | F | |||||
| T | F | T | |||||
| T | F | F |
In: Math
A researcher wants to assess association between high blood pressure prevalence and the amounts of processed foods. If the level of education is associated with both amounts of processed food and high blood pressure, is education a confounder or effect modifier?
In: Math
Mini-Case Study 3: Debt Spending
A study found that American consumers are making average monthly debt payments of $983 (Experian.com- November 11th, 2010). However, the study of 26 metropolitan areas reveals quite a bit of variation in debt payments, depending on where consumers live. For example, the Washington, DC, residents pay the most ($1,285 per month), while Pittsburghers pay the least ($763 per month). Madelyn Davis, an economist at a large bank, believes that income differences between cities are the primary reason for the disparate debt payments. For example, the Washington, DC, area’s high incomes have likely contributed to its placement at the top of the list. Madelyn also wonders about the likely effect of unemployment on consumer debt payments. She wonders areas with higher unemployment rates will leave consumers struggling to pay their bills and thus lower debt payments. On the other hand, higher unemployment rates may reduce consumer debt payments, as consumers forgo making major purchases such as homes and cars. In order to analyze the relationship between income, the unemployment rate, and consumer debt payments, Madelyn gathers data from the same 26 metropolitan areas used in the debt payment study. Specifically, she collects each area’s 2010-2011 median household income as well as the monthly unemployment rate and average consumer debt for August 2010.
| Metropolitan area | Debt | Inc | Unemp |
| Washington, D.C. | 1,285 | 103.5 | 6.3 |
| Seattle | 1,135 | 81.7 | 8.5 |
| Baltimore | 1,133 | 82.2 | 8.1 |
| Boston | 1,133 | 89.5 | 7.6 |
| Denver | 1,104 | 75.9 | 8.1 |
| San Francisco | 1,098 | 93.4 | 9.3 |
| San Diego | 1,076 | 75.5 | 10.6 |
| Sacramento | 1,045 | 73.1 | 12.4 |
| Los Angeles | 1,024 | 68.2 | 12.9 |
| Chicago | 1,017 | 75.1 | 9.7 |
| Philadelphia | 1,011 | 78.3 | 9.2 |
| Minneapolis | 1,011 | 84 | 7 |
| New York | 989 | 78.3 | 9.3 |
| Atlanta | 986 | 71.8 | 10.3 |
| Dallas | 970 | 68.3 | 8.4 |
| Phoenix | 957 | 66.6 | 9.1 |
| Portland | 948 | 71.2 | 10.2 |
| Cincinnati | 920 | 69.5 | 9.3 |
| Houston | 889 | 65.1 | 8.7 |
| Columbus | 888 | 68.6 | 8.3 |
| St. Louis | 886 | 68.3 | 9.9 |
| Miami | 867 | 60.2 | 14.5 |
| Detroit | 832 | 69.8 | 15.7 |
| Cleveland | 812 | 64.8 | 9.6 |
| Tampa | 791 | 59.4 | 12.6 |
| Pittsburgh | 763 | 63 | 8.3 |
Madelyn asks for your group’s help to:
Use the ‘Data Analysis Toolpack’ to fit a regression. Be sure to include all steps including interpreting the model. Be thorough in describing your process. (20 points)
Use your final equation to predict the average debt payment of a metropolitan area whose median income is $41,203 and whose unemployment rate is 8.04%. (3 points)
Does the intercept have meaning? (3 points)
In: Math
The Office of the Superintendent of Bankruptcy of Canada (OSBC) is developing a new index to measure the vulnerability of firms in the new technology industry. The index is a ratio of current assets to current liabilities adjusted for various factors specific to this industry. The OSBC wants to compare the index among healthy and failed firms for validation purposes. They expect that failed firms should have a lower index than the healthy ones. Based on a Canadian business registry, they draw a random sample of 68 firms still in operations and another random sample of 33 firms which failed in the last 3 years.
Healthy Failed
1.50 0.82
2.08 0.05
2.23 1.68
0.89 0.91
1.91 1.16
1.20 0.42
1.95 0.88
2.73 1.11
1.62 2.03
1.71 0.92
1.03 0.73
1.96 0.89
0.10 0.83
1.43 0.99
2.50 0.52
0.23 1.32
1.67 0.48
2.17 1.10
2.61 0.19
1.56 0.51
1.76 0.26
1.02 0.88
1.80 1.31
1.81 0.90
1.76 0.62
0.68 1.45
2.02 1.17
1.20 0.93
1.87 0.75
2.61 0.13
1.11 1.12
2.73 1.15
2.22 0.71
2.50
0.67
1.14
3.15
1.44
2.16
1.21
3.05
0.95
0.90
2.80
1.55
2.44
1.84
1.24
1.39
1.80
2.05
1.52
0.96
2.12
1.85
1.69
2.30
2.21
2.03
1.64
1.87
1.06
1.93
2.25
1.42
0.96
1.64
2.21
a) Use Minitab or other appropriate software to produce boxplots of the index values for the two groups of firms and comment on their distribution. 2
b) Use an appropriate statistical test to determine, at the 1% significance level, whether the data provide evidence of a higher average index for the healthy firms. Make sure you provide your manual calculations using the critical value approach.
c) Calculate manually a 99% one-sided confidence interval for the difference in the average index of healthy and failed firms and compare your results with b) above.
d) Use Minitab or other appropriate software to perform the calculations in b) and c) above and comment on any differences.
In: Math
| According to the National Automobile Dealers Assoc., 75% of U.S. car dealers' profits comes from | ||||||||||
| repairs and parts sold. However, many of the dealerships' service departments aren't open evenings | ||||||||||
| or weekends. The percentage of dealerships opened during the evenings and weekends are as | ||||||||||
| follows: | ||||||||||
| Time Dealerships are Open | Percentage of Dealerships | |||||||||
| Weekends but not evenings | 37.5 | |||||||||
| Evenings but not weekends | 13.2 | |||||||||
| Both evenings and weekends | 11.3 | |||||||||
| a. Are the listed times mutually exclusive? | ||||||||||
| b. What is the probability that a car dealership selected at random is not open in the | ||||||||||
| evenings or on the weekends? | ||||||||||
| c. Suppose two car dealerships, say, Dealership A and Dealership B, are each selected at | ||||||||||
| random from car dealerships in the United States. What is the probability that both are open | ||||||||||
| in the evenings but not on the weekends, or that both are open on the weekends but not in | ||||||||||
| the evenings? | ||||||||||
| d. For the two dealerships in part c, what is the probability that Dealership A is open in the | ||||||||||
| evenings but not on the weekends, and Dealership B is open on the weekends but not in the | ||||||||||
| evenings? | ||||||||||
| e. For the two dealerships in part c, what is the probability that one of them is open in the | ||||||||||
| evenings but not on the weekends, and that the other is open on the weekends but not in the | ||||||||||
| evenings? | ||||||||||
In: Math
A) If four babies are born in a given hospital on the
same day, what is the probability that all four will be boys?
B) if four babies are born in a given hospital on the same day,
what is the probability that 3 will be girls and 1 will be a
boy?
C) You flip a coin twice what is the probability that it lands on
heads once and tails one?
In: Math
Please show your calculations and steps. In a recent national survey, 30 Canadian adults aged 18-24 reported having used cannabis for the first time since its legalisation in 2018 compared to 68 among the 25-44-year-olds. Out of the 1500 survey respondents, 125 were 18-24-year-olds and 400 were in the 25-44 age group. The Public Health Agency has been concerned that the first time use of cannabis among the younger cohort is higher than that among the older cohort.
a) Formulate the appropriate statistical hypotheses to test if the proportion of first-time cannabis users is higher among younger adults.
b) Perform the appropriate hypothesis test manually using the P-value approach and a 2% significance level. Make sure you verify that the relevant assumptions and conditions are met for the test.
c) Using the corresponding confidence level, calculate a one-sided confidence interval for the difference in the proportions of first-time cannabis users among the two age groups.
d) Are the results from b) and c) above consistent and why? e) Use Minitab or other appropriate software to perform the calculations in b) and c) and comment on any differences.
In: Math
Identify at least three different qualitative data collection instruments (e.g. in-depth interviews, focus groups, etc.) and how they can be used in a study.
In: Math
1. When a pair of balanced dice is rolled. Let A = {the sum of the dice is 10}, B = {doubles are rolled}. Find P(A), P(B).
2. Four couples are randomly sat in a row. How many different ways possible if
(a) no restriction; (b) all men have to sit together and all women have to sit together; (c) one of the couples have to sit together.
3.Two events A and B are investigated. P(A) = 0.35, P(B) = 0.72, the percent of chance that at least one of the event A or B occur is 90%. What is the probability that only one of the events happens
In: Math
Data Structures for R studio
In: Math
1. A researcher wanted to estimate the mean
contributions made to charitable causes by all major companies. A
random sample of 18 companies produced by the following data on
contributions (in millions of dollars) made by them.
1.8, 0.6, 1.2, 0.3, 2.6, 1.9, 3.4, 2.6, 0.2
2.4, 1.4, 2.5, 3.1, 0.9, 1.2, 2.0, 0.8, 1.1
Assume that the contributions made to charitable
causes by all major companies have a normal distribution.
a. What is the point estimate for the population mean?
b. Construct a 98% confidence interval for the population
mean.
c. What sample size would the researcher need to obtain a margin of
error of 100,000 for the same confidence level? (Assume that the
sample standard deviation obtained from his original sample is
equal to the population standard deviation.)
d. Prior to collecting the data, the researcher believed that the
mean contribution of all companies was less than $2.5 million. For
a significance level of 0.01, test the researchers hypothesis.
In: Math
A trucking company would like to compare two different routes
for efficiency. Truckers are randomly assigned to two different
routes. Twenty truckers following Route A report an average of 49
minutes, with a standard deviation of 5 minutes. Twenty truckers
following Route B report an average of 54 minutes, with a standard
deviation of 3 minutes. Histograms of travel times for the routes
are roughly symmetric and show no outliers.
a) Find a 95% confidence interval for the difference in the
commuting time for the two routes.
b) Does the result in part (a) provide sufficient evidence to
conclude that the company will save time by always driving one of
the routes? Explain.
a) The 95% confidence interval for the difference in the
commuting time for the two routes muBminusmuA is (
nothing minutes,
nothing minutes).
In: Math
Listed below are annual data for various years. The data are weights (metric tons) of imported lemons and car crash fatality rates per 100,000 population. Construct a scatterplot, find the value of the linear correlation coefficient r, and find the P-value using α = 0.05. Is there sufficient evidence to conclude that there is a linear correlation between lemon imports and crash fatality rates? Do the results suggest that imported lemons cause car fatalities?
|
Lemon Imports |
231 231 |
265 265 |
358 358 |
483 483 |
531 531 |
||
|
Crash Fatality Rate |
15.8 15.8 |
15.6 15.6 |
15.5 15.5 |
15.3 15.3 |
14.8 14.8 |
What are the null and alternative hypotheses?
A.
H0: ρ=0
H1: ρ ≠0
B.
H0: ρ ≠0
H1: ρ =0
C.
H0: ρ=0
H1: ρ <0
D.
H0: ρ=0
H1: ρ >0
Construct a scatterplot. Choose the correct graph below.
The linear correlation coefficient r is _____ .
(Round to three decimal places as needed.)
The test statistic t is ____.
(Round to three decimal places as needed.)
The P-value is _______.
(Round to three decimal places as needed.)
Because the P-value is ______ (greater / less) than the significance level 0.05, there _______(is not / is) sufficient evidence to support the claim that there is a linear correlation between lemon imports and crash fatality rates for a significance level of α= 0.05.
Do the results suggest that imported lemons cause car fatalities?
A.
The results do not suggest any cause-effect relationship between the two variables.
B.
The results suggest that an increase in imported lemons causes in an increase in car fatality rates.
C.
The results suggest that imported lemons cause car fatalities.
D.
The results suggest that an increase in imported lemons causes car fatality rates to remain the same.
In: Math