Finish times (to the nearest hour) for 10 dogsled teams are shown below.
Make a frequency table showing class limits, class boundaries, midpoints, frequency, relative frequencies, and cumulative frequencies. Use three classes.
(Round your answer for relative frequency to one decimal place and for midpoint to the nearest whole number.) 283 265 236 310 275 301 287 258 299 280
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Write out a chart or explain in writing how you would conduct an experiment on retroactive interference. Make sure to clearly indicate what is given to both the control and experimental groups. (6 Points)
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Find the best regression equation that gives selling price as a function of living area, taxes, acreage and rooms.
| House Selling Price | |||||
| Problem taken from Triola. Elementary Statistics. Addison-Wesley | |||||
| House | Selling Price | Living Area | Taxes | Acreage | Rooms |
| $1,000 | 100 sq. ft | $1,000 | |||
| 1 | 145 | 15 | 1.9 | 2 | 5 |
| 2 | 228 | 38 | 3 | 3.6 | 11 |
| 3 | 150 | 23 | 1.4 | 1.8 | 9 |
| 4 | 130 | 16 | 1.4 | 0.53 | 7 |
| 5 | 160 | 16 | 1.5 | 0.5 | 7 |
| 6 | 114 | 13 | 1.8 | 0.31 | 7 |
| 7 | 142 | 20 | 2.4 | 0.75 | 9 |
| 8 | 265 | 24 | 4 | 2 | 7 |
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A growing concern of employers is time spent in activities like surfing the Internet and e-mailing friends during work hours. The San Luis Obispo Tribune summarized the fundings from a survey of a large sample of workers in an article that ran under the headline "Who Goofs Off 2 Hours a Day? Most Workers, Survey Says" (August 3, 2006). Suppose that the CEO of a large company wants to determine whether the average amount of waisted time during an 8-hour work day for employees of her company is less than the reported 120 minutes. Each person in a random sample of 12 employees was contacted and asked about daily waisted time at work. The resulting data are the following:
108 112 117 128 130 111 131 116 113 113 105 128
The CEO wants to determine if these data provide evidence that the mean wasted time for this company is less than 120 minutes. Assuming that the population distribution is approximately normal, find the P-value for this test.
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Make the following:
a. frequency distribution
b. pareto chart
c. probability distribution
d. pie graph
for the following set of numbers :
Prophecy - 15 out of 50
Advice - 7 out of 50
Wisdom - 17 out of 50
Compliments - 4 out of 50
Misc. - 7 out of 50
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Regression analysis consists of two major tasks: (i) estimation of population parameters and (ii) hypothesis testing (e.g., t-test, F-test) or the application of inferential statistics to the estimated parameters. We learned OLS (ordinary least square) principle as the major estimation tool (thereby fulfilling the first task). There is a critically important assumption that we have to make in order to perform the second task (that is, to conduct hypothesis testing with respect to estimated parameters). Identify and discuss it. (10 points)
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A study of fox rabies in a country gave the following information about different regions and the occurrence of rabies in each region. A random sample of
n1 = 16
locations in region I gave the following information about the number of cases of fox rabies near that location.
x1:
Region I Data
| 2 | 9 | 9 | 9 | 7 | 8 | 8 | 1 |
| 3 | 3 | 3 | 2 | 5 | 1 | 4 | 6 |
A second random sample of
n2 = 15
locations in region II gave the following information about the number of cases of fox rabies near that location.
x2:
Region II Data
| 2 | 2 | 5 | 2 | 6 | 8 | 5 | 4 |
| 4 | 4 | 2 | 2 | 5 | 6 | 9 |
(i) Use a calculator with sample mean and sample standard deviation keys to calculate x1 and s1 in region I, and x2 and s2 in region II. (Round your answers to two decimal places.)
| x1 | = |
| s1 | = |
| x2 | = |
| s2 | = |
(ii) Does this information indicate that there is a difference
(either way) in the mean number of cases of fox rabies between the
two regions? Use a 5% level of significance. (Assume the
distribution of rabies cases in both regions is mound-shaped and
approximately normal.)
(a) What is the level of significance?
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PROBLEM:
The average hourly wage of carpenters is normally distributed with a population mean of $62.00 and a population standard deviation of $8.00. Calculate the following:
(a) The proportion of carpenters earning between $48 and $50.
(b) The proportion of carpenters earning more than $67.
(c)The proportion of carpenters earning less than $52.
(d) The 85th percentile.
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What is the equipment variation as a percent of process variation using ANOVA
Part Appraiser Trial
Measurement
1 1 1 12.369
1 1 2 11.957
1 2 1 12.915
1 2 2 13.065
1 3 1 13.894
1 3 2 13.86
1 4 1 15.055
1 4 2 15.081
2 1 1 18.26
2 1 2 18.271
2 2 1 19.068
2 2 2 19.089
2 3 1 20.197
2 3 2 20.176
2 4 1 20.665
2 4 2 20.553
3 1 1 19.607
3 1 2 19.749
3 2 1 20.478
3 2 2 20.374
3 3 1 20.402
3 3 2 20.454
3 4 1 22.133
3 4 2 22.405
4 1 1 26.056
4 1 2 25.813
4 2 1 26.895
4 2 2 26.921
4 3 1 28.991
4 3 2 28.981
4 4 1 30.695
4 4 2 30.872
5 1 1 28.498
5 1 2 28.723
5 2 1 31.671
5 2 2 31.678
5 3 1 33.357
5 3 2 33.385
5 4 1 34.607
5 4 2 34.511
6 1 1 37.184
6 1 2 37.029
6 2 1 37.806
6 2 2 37.809
6 3 1 38.379
6 3 2 38.493
6 4 1 39.25
6 4 2 38.848
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Find and sketch the critical value(s) and the rejection region for a left-tailed t-test with α =0.02 and n=42.
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Directions: Solve the following problems, detailing and documenting the solutions. Additional instructions: For each problem, be sure to include the (a) type of parametric or nonparametric testing being performed; (b) both null and research hypotheses; (c) critical value and test statistic; (d) p-value; and (e) both technical and contextual conclusions. 1. The back offices for the five department stores that anchor Pinelands Promenade Mall dispute whether or not they receive comparable treatment by mall management. In response, mall management hired a consulting firm to investigate whether or not customer preferences among shoppers for these five department stores are comparable or equivalent. Research assistants collected a random sample of 240 people at the mall, asking these mall visitors which department store they preferred most. The resulting frequency data was as follows: Onyx Paisley’s Quarterdeck Regal Sale-Mart 54 60 36 48 42 What should the consulting firm report to mall management? In other words, according to the available evidence, and testing at the 5% level of significance, is the proportion of mall visitors who prefer each of the five department stores at Pinelands Promenade the same? [COMMENTS & HINTS: It is good to see how the data fits the claim.]
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Computers Magazine has recently completed an analysis of its customer base. It has determined that 75% of the issues sold each month are subscriptions and the other 25% are sold at newsstands. It has also determined that the ages of its subscribers are normally distributed with a mean of 44.5 and a standard deviation of 7.42 years, whereas the ages of its newsstand customers are normally distributed with a mean of 36.1 and a standard deviation of 8.20 years.
(a) Computers Magazine would like to make the following statement to its advertisers: “80% of our subscribers are between the ages of . . . and . . . .” Your job is to fill in the blanks, choosing a range that is symmetric around the mean. (In other words, the mean age of subscribers should be the midpoint of the range.)
(b) What proportion of Computers Magazine newsstand customers have ages in the range you gave in (a)?
(c) What proportion of all of Computers Magazine customers have ages in the range you gave in (a)?
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RESUBMITTING AS PREVIOUS SUBMISSION BY ANONYMOUS WAS INCORRECT
The accompanying table contains the service ratings of 14 different Internet and TV providers. Level of significance is .10. Complete parts (a) through (d) below
Determine the T Test
Determine the P value
Construct and interpret a 90% confidence interval estimate of the difference in the mean service rating between TV and Internet services
| Provider | TV | Internet |
| 1 | 71 | 74 |
| 2 | 71 | 75 |
| 3 | 62 | 65 |
| 4 | 72 | 77 |
| 5 | 64 | 66 |
| 6 | 61 | 62 |
| 7 | 52 | 55 |
| 8 | 66 | 71 |
| 9 | 63 | 66 |
| 10 | 74 | 78 |
| 11 | 58 | 61 |
| 12 | 69 | 73 |
| 13 | 65 | 69 |
| 14 | 66 | 71 |
In: Math
Baseball Players Basketball Players Football Players
32 27 16
27 36 13
26 25 15
35 30 10
Step 1: State Hypotheses (2 points)
Step 2: Determine Comparison Distribution (1 point)
Step 3: Set the Criteria for a Decision (3 points)
dfW=
Step 3: Compute the Test Statistic (10 points)
Step 5: Make a Decision (9 points)
Reject/Fail to Reject the null?
If necessary, compute a Tukey’s HSD post hoc test.
Write your results as they would appear in a research journal (~two sentences).
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The correct degrees of freedom for a dependent samples ttest with 55 participants in each group would be equal to ________.
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