The times (in seconds) for a sample of New York Marathon runners were as follows:
Gender |
Age Class |
||
Male |
20-29 |
30-39 |
40+ |
13615 |
14677 |
14528 |
|
18784 |
16090 |
17034 |
|
14256 |
14086 |
14935 |
|
10905 |
16461 |
14996 |
|
12077 |
20808 |
22146 |
|
Female |
16401 |
15357 |
17260 |
14216 |
16771 |
25399 |
|
15402 |
15036 |
18647 |
|
15326 |
16297 |
15077 |
|
12047 |
17636 |
25898 |
Conduct a two-way analysis of variance including interactions to examine these data. Perform model criticism. What do you conclude? Note that R users do not need to invoke the “car” package since the equal replication means that Type I = Type III SS (using car package can be tricky when fitting models with interactions since the contrasts also need to be altered to make them comparable).
In: Statistics and Probability
You may need to use the appropriate appendix table or technology to answer this question.
A simple random sample of 400 individuals provides 128 Yes responses.
(a)
What is the point estimate of the proportion of the population that would provide Yes responses?
(b)
What is your estimate of the standard error of the proportion,
σp?
(Round your answer to four decimal places.)
(c)
Compute the 95% confidence interval for the population proportion. (Round your answers to four decimal places.)
to
In: Statistics and Probability
In: Statistics and Probability
Anystate Auto Insurance Company took a random sample of 380
insurance claims paid out during a 1-year period. The average claim
paid was $1580. Assume σ = $268.
Find a 0.90 confidence interval for the mean claim payment. (Round
your answers to two decimal places.)
lower limit | $ |
upper limit | $ |
Find a 0.99 confidence interval for the mean claim payment. (Round
your answers to two decimal places.)
lower limit | $ |
upper limit | $ |
In: Statistics and Probability
This problem is based on problems 11.4 & 11.5
from Lomax & Hahs-Vaughn, 3rd ed.
The following three independent random samples are obtained from
three normally distributed populations with equal variance. The
dependent variable is starting hourly wage, and the groups are the
types of position (internship, co-op, work study).
Group 1: Internship | Group 2: Co-op | Group 3: Work Study |
---|---|---|
11 | 12.5 | 10 |
13 | 11.75 | 14 |
12.25 | 12 | 14.75 |
11.75 | 11.5 | 12.5 |
11.75 | 11.25 | 13.75 |
14 | 11.5 | 12.25 |
11 | 10.5 | 12.5 |
9.25 | 12.25 | 15 |
12 | 11.5 | 11.75 |
12.5 | 13.25 | 15 |
13.75 | 11.5 | 12 |
Do not forget to convert this table from parallel format
(i.e., groups in each column) to serial format for analysis in
SPSS.
Use SPSS (or another statistical software package) to conduct a
one-factor ANOVA to determine if the group means are equal using
α=0.02α=0.02. Though not specifically assessed here, you are
encouraged to also test the assumptions, plot the group means, and
interpret the results.
Group means (report to 2 decimal places):
Group 1: Internship:
Group 2: Co-op:
Group 3: Work Study:
ANOVA summary statistics:
F-ratio =
(report accurate to 3 decimal places)
p=p=
(report accurate to 4 decimal places)
Conclusion:
In: Statistics and Probability
Is there a relationship between the number of stories a building has and its height? Some statisticians compiled data on a set of n = 52 buildings reported in the 1994 World Almanac. You will use the data set to decide whether height can be predicted from the number of stories. (a) Load the data from buildings.txt (Note that this is a text file, so use the appropriate instruction. If you are having trouble uploading the data, open it to see its contents and type the data in: one vector for heights and one vector for stories. Ignore the year data.) (b) Draw a scatterplot with stories in the x-axis and height in the y-axis. Does there seem to be a linear relationship between the two variables? (c) Find the linear correlation coefficient between these variables. What does it tell you about the linear relationship? (d) Obtain the linear model and summary. Write down the regression equation that relates height with stories. Add the line to the scatterplot. (e) Test for significance of the regression at = 0.05. State the null and alternative hypotheses. Can the model be used for predictions? Justify your conclusion using the summary in (d). (f) State the coefficient of determination. What percentage of variation in height is explained by the number of stories? (g) Draw diagnostic plots (a plot of stories vs. residuals, and a normal probability plot for the residuals). Do assumptions appear to be satisfied?
YEAR Height Stories 1990 770 54 1980 677 47 1990 428 28 1989 410 38 1966 371 29 1976 504 38 1974 1136 80 1991 695 52 1982 551 45 1986 550 40 1931 568 49 1979 504 33 1988 560 50 1973 512 40 1981 448 31 1983 538 40 1968 410 27 1927 409 31 1969 504 35 1988 777 57 1987 496 31 1960 386 26 1984 530 39 1976 360 25 1920 355 23 1931 1250 102 1989 802 72 1907 741 57 1988 739 54 1990 650 56 1973 592 45 1983 577 42 1971 500 36 1969 469 30 1971 320 22 1988 441 31 1989 845 52 1973 435 29 1987 435 34 1931 375 20 1931 364 33 1924 340 18 1931 375 23 1991 450 30 1973 529 38 1976 412 31 1990 722 62 1983 574 48 1984 498 29 1986 493 40 1986 379 30 1992 579 42
*********************************
Need R console code
In: Statistics and Probability
In: Statistics and Probability
1). Calculate the specific correlation coefficient for this data. What does rxy = ? You can use the table on the last page for your calculations (This is the tough one).
2). Does there appear to be a correlation between these two variables? If yes, in what direction (positive or negative)?
3). What are three possible explanations for this correlational relationship? (Note – These can include “third variable” explanations).
Subject # |
X |
Y |
X2 |
Y2 |
XY |
1 |
0 |
9 |
0 |
81 |
0 |
2 |
0 |
7 |
0 |
49 |
0 |
3 |
1 |
6 |
1 |
36 |
6 |
4 |
1 |
7 |
1 |
49 |
7 |
5 |
1 |
8 |
1 |
64 |
8 |
6 |
2 |
5 |
4 |
25 |
10 |
7 |
2 |
6 |
4 |
36 |
12 |
8 |
2 |
7 |
4 |
49 |
14 |
9 |
3 |
3 |
9 |
9 |
9 |
10 |
3 |
4 |
9 |
16 |
12 |
11 |
3 |
5 |
9 |
25 |
15 |
12 |
4 |
3 |
16 |
9 |
12 |
13 |
4 |
4 |
16 |
16 |
16 |
14 |
5 |
3 |
25 |
9 |
15 |
15 |
5 |
4 |
25 |
16 |
20 |
16 |
5 |
5 |
25 |
25 |
25 |
17 |
6 |
5 |
36 |
25 |
30 |
18 |
7 |
4 |
49 |
16 |
28 |
19 |
8 |
4 |
64 |
16 |
32 |
20 |
9 |
3 |
81 |
9 |
27 |
Σ (Sum) |
71 |
102 |
379 |
580 |
298 |
In: Statistics and Probability
Fewer young people are driving. In year A, 67.9% of people under 20 years old who were eligible had a driver's license. Twenty years later in year B that percentage had dropped to 44.7%. Suppose these results are based on a random sample of 1,700 people under 20 years old who were eligible to have a driver's license in year A and again in year B.
(a)
At 95% confidence, what is the margin of error of the number of eligible people under 20 years old who had a driver's license in year A? (Round your answer to four decimal places.)
At 95% confidence, what is the interval estimate of the number of eligible people under 20 years old who had a driver's license in year A? (Round your answers to four decimal places.)
to
(b)
At 95% confidence, what is the margin of error of the number of eligible people under 20 years old who had a driver's license in year B? (Round your answer to four decimal places.)
At 95% confidence, what is the interval estimate of the number of eligible people under 20 years old who had a driver's license in year B? (Round your answers to four decimal places.)
to
(c)
Is the margin of error the same in parts (a) and (b)? Why or why not?
The margin of error in part (a) is ---Select--- smaller larger than the margin of error in part (b). This is because the sample proportion of eligible people under 20 years old who had a driver's license in year B is ---Select--- closer to 0 closer to 0.5 closer to 1 than the sample proportion of eligible people under 20 years old who had a driver's license in year A. This leads to a ---Select--- smaller larger interval estimate in part (b).
In: Statistics and Probability
The data show systolic and diastolic blood pressure of certain
people. Find the regression equation, letting the systolic reading
be the independent (x) variable. Find the best predicted diastolic
pressure for a person with a systolic reading of 150. Is the
predicted value close to 66.2, which was the actual diastolic
reading? Use a significance level of 0.05.
Systolic
139
118
145
133
141
138
139
136
Diastolic
101
61
82
74
104
79
74
74
LOADING... Click the icon to view the critical values of the
Pearson correlation coefficient r.
In: Statistics and Probability
A simple linear least squares regression of the heights (in feet) of a building on the number of stories in the building was performed using a random sample of 30 buildings. The associated ANOVA F statistic was 5.60. What is the P-value associated with this ANOVA F test?
a.) greater than 0.10
b.) between 0.001 and 0.01
c.) between 0.01 and 0.025
d.) between 0.05 and 0.10
e.) between 0.025 and 0.05
f.) less than 0.001
In: Statistics and Probability
The number of computers per household in a small town Computers 0 1 2 3 Households 298 284 97 18
Find probability distribution
Graph using a histogram
Describe distribution shape
In: Statistics and Probability
Please solve using EXCEL SOLVER and show steps
1 – A company requires during the next four months, respectively, 50, 65, 100, and 70 units of a commodity (no backlogging is allowed). Production costs are $5, $8, $4, and $7 per unit during these months. The storage cost from one month to the next is $2 per unit (assessed on ending inventory). It is estimated that each unit on hand at the end of month 4 could be sold for $6. Formulate an LP that will minimize that the net cost incurred in meeting the demands of the next four months. Solve the problem using Solver by Excel. Find the range of values for production costs which the current basis remains optimal.
Hint: Decision variables are production during each month and inventory at the end of each month.
In: Statistics and Probability
In: Statistics and Probability
In 2018 in an attempt to improve the reputation of the
Democratic People’s Republic of Korea (DPRK) lottery tickets were
sold to people around the world. The grand prize of this lottery
was a weekend with Kim Jung Un. During anevening with Kim Jung Un
the lottery winner was offered a meal made from one of the lobsters
in Kim Jung Un’s private lobster aquarium.(Which by the way are all
Maine lobsters!) The average weight of the lobsters was 22 ounces
and the standard deviation was 0.67 ounces. When a random lobster
wastaken from Kim Jung Un’s aquarium what was the probability it
weighed more than 23.75 ounces?
a.) 0.0154 b.) 0.9955 c.) 0.9846 d.) 0.0045 e.)None of these
In lieu of using a single resistor three resistors are wired in
series. The three resistors are identical. The resistance o f each
is normally distributed with a mean of 6 ohms and a standard
deviation of 0.3 ohms. The probability the combined resistance will
exceed 19 ohm's is 0.0274. How precise (i.e. what is the required
value of the standard deviation) would the manufacturing process
have to be make the probability less than 0.0055 that t he combined
resistance of the circuit would exceed 19 ohms?
a.) 0.180 ohms b.) 0.220 ohms c.) 0.227 ohms d.) 0.229 ohms e.)
None of these
An experiment has two possible outcomes: the first occurs with
probability p ; the second with probability p^2 . What is p?
a.) 0.3820 b.) 0.5000 c.)
0.2500 d.) 0.6180 e.) None of
the above
Of all 3–to–5year old children, 56% are enrolled in school. If a
sample of 500 such children is randomly selected, find the
probability that at least 250 will be enrolled in school.Hint: Use
De Moivre–Laplace.
a.) 0.9970 b.) 0.0035 c.) 0.9965 d.) 0.0030 e.) None of the
above
In: Statistics and Probability