State of Nature |
||
Decision Alternative |
High Demand (S1) |
Low Demand (S2) |
Order 1 lot, D1 |
60 |
50 |
Order 2 lots, D2 |
80 |
30 |
Order 3 lots, D3 |
100 |
10 |
P(Sj) |
0.4 |
0.6 |
In: Statistics and Probability
1) A researcher would like to determine if relaxation training affects the number of headaches for chronic headache sufferers. For a week prior to training, each participant records the number of headaches suffered. Participants then receive relaxation training and for the week following training the number of headaches is again measured. The data are as follows: before: 6, 5, 3, 3, 6, 2, 4, 4 and after: 4, 1, 3, 1, 2, 1, 3, 2.
a. Do the results indicate a significant difference? Use a two-tailed test with α = .05. State the null hypothesis and the tcritical you will use to evaluate the null hypothesis.
b. Compute Cohen’s d and r2 to measure the size of the effect. Conclude with a separate summary statement for each measure of effect size that is appropriate for publication in a scientific journal.
In: Statistics and Probability
State of Nature |
||
Decision Alternative |
S1 |
S2 |
D1 |
100 |
300 |
D2 |
400 |
200 |
P(F) = 0.56 P(S1/F) = 0.57 P(S1/U) = 0.18 P(S1) = 0.40
P(U) = 0.44 P(S2/F) = 0.43 P(S2/U) = 0.82 P(S2) = 0.60
In: Statistics and Probability
Employee |
A Birth Place |
B Monthly Salary (Nearest Dollar) |
C Current Rating |
D Rating Score (1.0 – 5.0) |
E Driving Distance Residence to Office (Miles) |
F Parking Permits Issued |
Sue |
Williamsburg, VA |
2,916 |
Meets |
3.2 |
2.3 |
1 |
Fred |
Boone, NC |
2,500 |
Below |
1.8 |
20.2 |
1 |
Mark |
Key West, FL |
1,000 |
Meets |
2.9 |
0.5 |
0 |
Dontay |
Smugglers Notch, VT |
2,000 |
Exceeds |
4.3 |
365.4 |
1 |
Margie |
Muleshoe, TX |
1,900 |
Meets |
3.0 |
5.7 |
2 |
Blake |
Lancaster, PA |
4,500 |
Meets |
3.4 |
1.6 |
1 |
List the column letter(A,B,C,D,E,F) associated with the following questions.
a. Which variables arecategorical (qualitative)? Answer: ___________________
b. Which variables are numerical (quantitative)?Answer: ___________________
c. Which of the variables, if any, arediscrete? Answer: ___________________
d. Which variables, if any, are continuous? Answer: ___________________
e. Which variables, if any, requireanIntervalScale? Answer: ________________
f. Which variables, if any, requirean OrdinalScale? Answer: ________________
g. Which variables, if any, requirea NominalScale? Answer: ________________
h. Which variables, if any, requirea Ratio Scale? Answer: _______________
In: Statistics and Probability
Political parties want to know what groups of people support them. The General Social Survey (GSS) asked its 2014 sample, "Generally speaking, do you usually think of yourself as a Republican, Democrat, Independent, or what?" The GSS is essentially an SRS of American adults. Here is a large two-way tale breaking down the responses by the highest degree the subject held:
None | High School | Junior College | Bachelor | Graduate | |
Strong Democrat | 53 | 198 | 23 | 81 | 64 |
Not strong Democrat | 52 | 204 | 31 | 70 | 49 |
Independent, near Dem. | 40 | 163 | 26 | 66 | 42 |
Independent | 118 | 251 | 36 | 67 | 30 |
Independent, near Rep. | 24 | 136 | 19 | 45 | 25 |
Not strong Republican | 19 | 142 | 30 | 71 | 30 |
Strong Republican | 18 | 131 | 15 | 53 | 28 |
Other Party | 5 | 31 | 3 | 15 | 8 |
1. Make a 2x5 table by combining the counts in the three rows that mention Democrats, Republicans and ignoring strict independents and supporters of other parties. We might think of this table as comparing all adults who lean Democrat or Republican. How does does support for the two major parties differ among adults with different levels of education?
2. Use the full table to analyze the differences in political party support among levels of education. The sample is so large that the differences are bound to be highly significant. but give the χ2χ2 test statistic and p-value nonetheless. The main challenge is in seeing what the data say. Does the full table yield any insights not found in the compressed table analyzed in part 1?
In: Statistics and Probability
The following are advertised sale prices of color televisions at an electronics store.
Size (inches) | Sale Price ($) |
---|---|
9 | 147 |
20 | 187 |
27 | 267 |
31 | 447 |
35 | 1177 |
40 | 2177 |
60 | 2497 |
Calculate the least squares line. Put the equation in the form of:
ŷ = a + bx
Find the correlation coefficient r.
Find the estimated sale price for a 33-inch television. (Use
your equation from part (d). Round your answer to two decimal
places.)
$
Find the estimated sale price for a 47-inch television
What is the slope of the least squares (best-fit) line? (Round
your answer to three decimal places.)
In: Statistics and Probability
2. Suppose a randomly chosen group of 150 high school juniors and seniors who took the SAT twice over a period of six months showed an average improvement on the second SAT of 25 points. The standard deviation of the difference in the scores between the first and second SAT was 20 points.
a. What is the appropriate design for this situation?
b. Set up an appropriate hypotheses to test the claim that the score on the second SAT is, on average at least 20 points higher than on the first SAT.
c. Test the hypotheses stated in part b. What distribution should be used? What assumptions, if any, should be checked? Explain. Make a decision and give a conclusion.
In: Statistics and Probability
The graph illustrates a normal distribution for the prices paid
for a particular model of HD television. The mean price paid is
$1600 and the standard deviation is $140.
1180 1320 1460 1600 1740 1880 2020
Use the 68-95-99.7 Rule to answer the following questions.
What is the approximate percentage of buyers who paid more than
$2020?
%
What is the approximate percentage of buyers who paid more than
$1880?
%
What is the approximate percentage of buyers who paid between $1460
and $1740?
%
What is the approximate percentage of buyers who paid between $1460
and $1600?
%
What is the approximate percentage of buyers who paid between $1600
and $2020?
%
What is the approximate percentage of buyers who paid between $1600
and $1880?
In: Statistics and Probability
Price of eggs and milk: The following table presents the average price in dollars for a dozen eggs and a gallon of milk for each month from January through October
2010
.
Dozen Eggs |
Gallon of Milk |
1.79 |
3.12 |
1.77 |
2.69 |
1.28 |
3.76 |
1.78 |
2.78 |
0.88 |
3.00 |
0.98 |
3.08 |
1.15 |
3.31 |
1.05 |
3.15 |
1.86 |
2.94 |
1.83 |
2.73 |
If the price of eggs differs by $0.25 from one month to the next, by how much would you expect the price of milk to differ? Round the answer to two decimal places.
In: Statistics and Probability
In: Statistics and Probability
Age | 58 | 69 | 43 | 39 | 63 | 52 | 47 | 31 | 74 | 36 |
Cholesterol level | 189 | 235 | 193 | 177 | 154 | 191 | 213 | 165 | 198 | 181 |
(3) (Continued from Question 2) Based on the sample of 10 men with ages and cholesterol levels given in the table in Question 2, answer the following.
(a) At 5% significance level, do the data provide sufficient evidence to conclude that age is useful as a (linear) predictor of cholesterol level? State any assumption(s) you make.
(b) What is the mean estimated cholesterol level for all 74 year old men?
(c) Find a 90% confidence interval for mean cholesterol level for all 74 year old men.
(d) Find a 90% prediction interval for mean cholesterol level for all 74 year old men.
(e) If we wish to add one dummy predictor variable to make a multiple regression model, what would it be?
please show me the math for this
In: Statistics and Probability
The data
You have been given data from red maple and white oak trees from a national forest dominated by mixed hardwood stands. The following variables for each tree are included
Variable |
Description |
treecode |
Tree label |
location |
Eastern or western location in the forest |
Species |
Species codes (MR= red maple, OW=white oak) |
Dbh |
Diameter at breast height (1.3 m) in cm |
Height |
Height in m |
treecode,location,species,dbh,height 1-W-7,eastern,MR,46.8,39.2 1-N-1,eastern,MR,47.1,37.4 1-E-4,eastern,MR,60.6,41.1 2-M-2,eastern,MR,50.1,26.9 3-E-4,eastern,MR,16.4,25.2 3-M-6,eastern,MR,29.4,27.3 3-S-4,eastern,MR,33.3,38 3-N-5,eastern,MR,37.4,22.5 3-N-6,eastern,MR,36.4,25 4-M-3,eastern,MR,7.2,3.9 4-M-2,eastern,MR,8,6.1 5-E-3,eastern,MR,19.6,14.5 7-N-5,eastern,MR,41.6,34.1 8-W-5,eastern,MR,31.7,31 8-S-7,eastern,MR,39.4,31.2 11-M-3,eastern,MR,16.3,24.3 11-M-5,eastern,MR,22.8,26.2 11-M-8,eastern,MR,23.4,30.8 11-M-4,eastern,MR,29.5,25.6 11-N-7,eastern,MR,37.5,27.6 11-S-6,eastern,MR,40.4,34.8 13-M-3,eastern,MR,31.8,27.7 13-M-2,eastern,MR,67.4,37.8 14-M-5,eastern,MR,31.1,28.7 14-M-4,eastern,MR,35.4,30.6 14-W-2,eastern,MR,34.3,33.3 14-E-3,eastern,MR,41.5,32.4 14-N-3,eastern,MR,39.1,36.8 14-M-3,eastern,MR,51,43.4 42-N-1,western,MR,57.6,35.9 43-M-4,western,MR,2.5,4.8 43-M-5,western,MR,3.4,4.8 43-M-7,western,MR,7,7 43-M-9,western,MR,10.5,9.7 44-M-3,western,MR,18.2,22.3 44-E-3,western,MR,25.6,25.3 45-M-1,western,MR,62.7,40 46-M-1,western,MR,25.6,28.3 46-M-2,western,MR,28.7,26.6 46-M-5,western,MR,43.9,26.8 46-N-9,western,MR,50.9,36.1 46-M-7,western,MR,56.3,35.2 47-N-1,western,MR,8.6,8.7 47-E-4,western,MR,22.6,19.3 48-M-2,western,MR,26,21.6 48-S-5,western,MR,30.7,23.5 49-M-7,western,MR,38.3,26.8 49-W-1,western,MR,45.4,29.6 50-M-5,western,MR,27,19 3-W-5,eastern,OW,6,6.5 3-W-3,eastern,OW,12.5,7.8 3-M-4,eastern,OW,19.1,25.2 3-M-3,eastern,OW,34.4,25.2 7-M-3,eastern,OW,31.7,24.2 7-S-1,eastern,OW,40.2,23 7-N-6,eastern,OW,45.5,25.2 7-N-7,eastern,OW,52.4,31.3 7-W-5,eastern,OW,54.3,28.3 8-M-2,eastern,OW,37.8,30.9 8-E-1,eastern,OW,65,36.4 8-M-4,eastern,OW,68.1,32.2 9-S-6,eastern,OW,59.8,46.9 11-M-2,eastern,OW,12.1,18.6 11-E-2,eastern,OW,17.7,12.4 48-M-7,western,OW,62.5,27.6 49-M-8,western,OW,3.7,4.4 49-N-4,western,OW,47.8,19.5 49-M-6,western,OW,53.4,29.6 49-M-4,western,OW,56,25.3 49-M-3,western,OW,67.4,27.4 50-N-2,western,OW,45.4,20.8 50-M-7,western,OW,48.1,23.9 50-M-4,western,OW,45.4,23.4 50-M-2,western,OW,48.7,22.7 52-N-6,western,OW,5.2,7 53-E-2,western,OW,44.3,30.6 53-N-2,western,OW,45.3,23.7 53-M-5,western,OW,76.9,28.6 54-M-6,western,OW,32.7,23.3 54-M-2,western,OW,40.2,24.1 54-S-6,western,OW,47.8,26.1 55-M-1,western,OW,49,27 55-M-2,western,OW,66.3,26.7 56-M-3,western,OW,29.3,18.8 57-M-3,western,OW,37.9,37.4 58-M-6,western,OW,41.9,22.4 59-M-2,western,OW,24.7,15.1 61-M-6,western,OW,57.3,30.6 62-M-10,western,OW,4.1,8.3 62-M-2,western,OW,9.1,2.7
trees = read.csv("C:/My Documents/ E-W MR-OW data.csv")
What kind of data is contained in the “species” variable? What kind of data is contained in the height variable
head(trees)
In: Statistics and Probability
The physicians in previous problem have been approached by a market research firm that offers to perform a study of the market at a fee of $5,000. The market researchers claim their experience enables them to use Bayes’ theorem to make the following statements of probability:
probability of a favorable market given a favorable study -----0.82 probability of an unfavorable market given a favorable study 0.18 probability of a favorable market given an unfavorable study 0.11 probability of an unfavorable market given an unfavorable
study-- 0.89 probability of a favorable research study ----------0.55 probability of an unfavorable research study----------------------0.45
a) Develop a new decision tree for the medical professionals to reflect the options now open with the market study.
b) Use the EMV approach to recommend a strategy.
c) What is the expected value of sample information? How much might
the
physicians be willing to pay for a market study?
d) Calculate the efficiency of this sample information.
In: Statistics and Probability
5. Speed (mph) Braking Distance (ft) 30 40 50 60 70 80
48 79 123 184 243 315. Find the Sx, Sy, Find correlation
coefficient, regression line y.
In: Statistics and Probability
The Titanic Used the data in the following table, which summarizes results from the sinking of the titanic.
Men |
Women |
Boys |
Girls |
|
Survived |
332 |
318 |
29 |
27 |
Died |
1360 |
104 |
35 |
18 |
In: Statistics and Probability