1. Out of a sample of 100 purchase orders, 10 contain errors. What is the confidence interval for 95% confidence?
2. For a 95% confidence level, what is the value n (sample size) when π = .15 and the sampling error is .07?
a.99.96
b.61.47
c. 96.04
d.51.00
In: Statistics and Probability
A random sample of professional wrestlers was obtained, and the annual salary (in dollars) for each was recorded. The summary statistics were x = 45,500 and n = 17. Assume the distribution of annual salary is normal with o = 8,500.
(a) Find a 90% confidence interval for the true mean annual salary for all professional wrestlers (in dollars). (Round your answers to four decimal places.)
(______________ , ______________) kg
In: Statistics and Probability
A population consists of the following five values: 2, 2, 30, 9, 30.
a. Not available in Connect.
b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answer to the nearest whole number.)
Sample means | |
Population mean | |
Both means are | (Click to select) equal not equal |
c. Compare the dispersion in the population with that of the sample means. Hint: Use the range as measure of dispersion.
The dispersion of the population is (Click to select) greater smaller than that of the sample means.
A population consists of the following five values: 2, 2, 30, 9, 30.
a. Not available in Connect.
b. By listing all samples of size 3, compute the mean of the distribution of the sample mean and the population mean. Compare the two values. (Round the final answer to the nearest whole number.)
Sample means | |
Population mean | |
Both means are | (Click to select) equal not equal |
c. Compare the dispersion in the population with that of the sample means. Hint: Use the range as measure of dispersion.
The dispersion of the population is (Click to select) greater smaller than that of the sample means.
In: Statistics and Probability
1) A random sample of the number of hours worked by 40 employees has a mean of 29.6 hours worked. Assume the population standard deviation is 7.9 hours.
a. Using a 95% confidence level, find the margin of error, E, for the mean number of hours worked.
2) In a study of 265 subjects, the average score on the examination was 63.8. Assume σ = 3.08.
a. What is a 95% confidence interval for ?
3) A college admissions director wishes to estimate the mean age of all students currently enrolled. In a random sample of 20 students, the mean age is found to be 22.9 years. From past studies, the standard deviation is known to be 1.5 years, and the population is normally distributed.
a. Construct a 90% confidence interval of the population mean age.
4) The weight of a product is measured in pounds. A sample of 50 units is taken from a batch. The sample yielded the following results: = 75 lbs., and σ = 10 lbs.
a. Calculate a 99% confidence interval for .
In: Statistics and Probability
The College Board provided comparisons of SAT scores based on the highest level of education attained by the test taker's parents. A research hypothesis was that students whose parents had attained a higher level of education would on average score higher on the SAT. This data set contains verbal SAT scores for a sample of students whose parents are college graduates and a sample of students whose parents are high school graduates. Use 0.01 as your level of significance.
College | High School |
485 | 442 |
534 | 580 |
650 | 479 |
554 | 486 |
550 | 528 |
572 | 524 |
497 | 492 |
592 | 478 |
487 | 425 |
533 | 485 |
526 | 390 |
410 | 535 |
515 | |
578 | |
448 | |
469 | |
College | High School |
485 | 442 |
534 | 580 |
650 | 479 |
554 | 486 |
550 | 528 |
572 | 524 |
497 | 492 |
592 | 478 |
487 | 425 |
533 | 485 |
526 | 390 |
410 | 535 |
515 | |
578 | |
448 | |
469 |
In: Statistics and Probability
In what follows use any of the following tests/procedures: Regression, multiple regression, confidence intervals, one sided T-test or two sided T-test. All the procedures should be done with 5% P-value or 95% confidence interval.Some answers are approximated, choose the most appropriate answer.Open Pollution data. SETUP: Is it reasonable to claim that cities with precipitation of less than 100 days have average temperature of less than 65 degrees F? Given the data your job is to confirm or disprove this claim.
I. What test/procedure did you perform? (6.66 points)
II. Statistical interpretation? (6.66 points)
III. Conclusion? (6.66 points)
CITY SO2 MANUF POP TEMP WIND PRECIP-INCHES PRECIP-#DAYS Phoenix 11 213 582 70.3 6 7.05 36 Little Rock 15 91 132 61 8.2 48.52 100 San Francisco 16 453 716 56.7 8.7 20.66 67 Denver 24 454 515 51.9 9 12.95 86 Hartford 82 412 158 49.1 9 43.37 127 Wilmington 43 80 80 54 9 40.25 114 Washington 30 434 757 57.3 9.3 38.89 111 Jacksonville 18 136 529 68.4 8.8 54.47 116 Miami 14 207 335 75.5 9 59.8 128 Atlanta 32 368 497 61.5 9.1 48.34 115 Chicago 131 3344 3369 50.6 10.4 34.44 122 Indianapolis 40 361 746 52.3 9.7 38.74 121 Des Moines 20 104 201 49 11.2 30.85 103 Wichita 10 125 277 56.6 12.7 30.58 82 Louisville 35 291 593 55.6 8.3 43.11 123 New Orleans 9 204 361 68.3 8.4 56.77 113 Baltimore 47 625 905 55 9.6 41.31 111 Detroit 46 1064 1513 49.9 10.1 30.96 129 Minneapolis-St. Paul 42 699 744 43.5 10.6 25.94 137 Kansas City 18 381 507 54.5 10 37 99 St. Louis 61 775 622 55.9 9.5 35.89 105 Omaha 17 181 347 51.5 10.9 30.18 98 Albuquerque 15 46 244 56.8 8.9 7.77 58 Albany 56 44 116 47.6 8.8 33.36 135 Buffalo 11 391 463 47.1 12.4 36.11 166 Cincinnati 27 462 453 54 7.1 39.04 132 Cleveland 80 1007 751 49.7 10.9 34.99 155 Columbus 27 266 540 51.5 8.6 37.01 134 Philadelphia 79 1692 1950 54.6 9.6 39.93 115 Pittsburgh 63 347 520 50.4 9.4 36.22 147 Providence 136 343 179 50 10.6 42.75 125 Memphis 10 337 624 61.6 9.2 49.1 105 Nashville 23 275 448 59.4 7.9 46 119 Dallas 11 641 844 66.2 10.9 35.94 78 Houston 10 721 1233 68.9 10.8 48.19 103 Salt Lake City 28 137 176 51 8.7 15.17 89 Norfolk 38 96 308 59.3 10.6 44.68 116 Richmond 38 197 299 57.8 7.6 42.59 115 Seattle 40 379 531 51.1 9.4 38.79 164 Charleston 40 35 71 55.2 6.5 40.75 148 Milwaukee 20 569 717 45.7 11.8 29.07 123
In: Statistics and Probability
NOTE :- Please find the probabilities as functions of cost
A service facility charges a $20 fixed fee plus $25 per hour of service up to 6 hours, and no additional fee is charged for a service visit exceeding 6 hours. Suppose that the service time τ again ranges from 0 to 10 hours, but now the probability density is twice as large during the middle 6 hours [2, 8] than during the outer 4 hours [0, 2] and [8, 10]. (Note as before that τ is a continuous random variable.) Let X represent the cost of service in the facility.
We would like to set up the probability density function (PDF) and the cumulative distribution function (CDF), then use them to analyze service fees.
Design Specifications
Sketch the probability density as a function of time. Be quantitative, and pay attention to units. Compute the probability that the service is greater than 6 hours. Then, sketch the probability density as a function of cost. Again, be quantitative and pay attention to units
Use the probability density function to set up the cumulative probability, also as a function of X.
In: Statistics and Probability
1. The following table gives the systolic blood pressure and age of patients.
Systolic Blood Pressure |
Age |
131 |
34 |
132 |
36 |
122 |
30 |
119 |
32 |
123 |
26 |
115 |
23 |
137 |
37 |
a) Determine an r value for this data and classify the value as weak, moderate, or strong.
b) Based on your calculated r value, what can you say about the slope of the regression line?
c) Determine the model equation. This is also called the regression line or the least squares line.
d) Refer to your notes around the assumptions of SLR. What is the value of∑ ? ? What is the mean of the error terms? How are the error terms distributed?
e) Calculate the values of the residuals and sum them.
f) Calculate the standard error, ?!, and ?", and describe the meaning of ?".
g) Conduct a hypothesis test at the 5% level of significance to test if the slope is significantly different from 0. What is the p – value? Determine a 95% confidence for ?#.
h) Suppose we want to predict the sbp for an average Age = 31. What would a 95% confidence interval be? (Notice that although the word predict is in the question, it specifically asks for the confidence interval.)
i) To predict the sbp, Y, for a person drawn at random who is aged 31, X, we would have 95% confidence in what interval? (Notice here the word confidence is used but it never specifically asks for a “confidence interval”. It just says 95% confidence in what interval. Here we are asking for a prediction interval)
In: Statistics and Probability
Give an example of a stochastic process that is:
(a) Both a Markov process and a martingale.
(b) A Markov process but not a martingale.
(c) A martingale but not a Markov process.
(d) Neither a Markov process nor a martingale.
In: Statistics and Probability
give the difference between anova, manova,mancova,pathanalysis,t-test,multiple regression and logistic regression
answrr only if you know otherwise dislike
In: Statistics and Probability
Production volume
400
450
550
600
700
750
Total cost
4000
5000
5400
5900
6400
7000
An important application of regression analysis in accounting
is in the estimation of cost. By collecting data on volume and cost
and using the least squares method to develop an estimated
regression equation relating volume and cost, an accountant can
estimate the cost associated with a particular manufacturing
volume. Consider the following sample of production volumes and
total cost data for a manufacturing operation. Excel File: data12-21.xls
|
In: Statistics and Probability
. A new vaccination is being used in a laboratory experiment to investigate whether it is effective. There are 252 subjects in the study. Is there sufficient evidence to determine if vaccination and disease status are related?
Vaccination Status Diseased Not Diseased Total
Vaccinated 51) 54) 105)
Not Vaccinated 54) 73) 147)
Total (125) (127) ( 252)
State the null and alternative hypothesis.
Find the value of the test statistic. Round your answer to three decimal places.
Find the degrees of freedom associated with the test statistic for this problem.
Find the critical value of the test at the 0.01 level of significance. Round your answer to three decimal places.
Make the decision to reject or fail to reject the null hypothesis at the 0.01 level of significance.
State the conclusion of the hypothesis test at the 0.01 level of significance.
In: Statistics and Probability
Define each of the following definitions concerning data:
Statistics, Skewed distribution, Histogram, Outliers, Sample space and Continuous variable
In: Statistics and Probability
Use SPSS, Excel or Minitab software to answer the following questions.
Generate normal random data with sample size, n = 40, mean = 20 and standard deviation = 11. Write the generated data in the following table.
Answer:
1 |
11 |
21 |
31 |
||||
2 |
12 |
22 |
32 |
||||
3 |
13 |
23 |
33 |
||||
4 |
14 |
24 |
34 |
||||
5 |
15 |
25 |
35 |
||||
6 |
16 |
26 |
36 |
||||
7 |
17 |
27 |
37 |
||||
8 |
18 |
28 |
38 |
||||
9 |
19 |
29 |
39 |
||||
10 |
20 |
30 |
40 |
Answer:
Answer
Answer
In: Statistics and Probability
a) A sample of 8 observations collected in a regression study on two variables, x(independent variable) and y(dependent variable). The sample resulted in the following data.
SSR=66, SST=86
Calculate an unbiased estimate of the variance of the error term epsilon.
b) A sample of 11 observations collected in a regression study on two variables, x(independent variable) and y(dependent variable). The sample resulted in the following data.
SSE=22, SSR=64
Calculate the coefficient of determination for the developed estimated regression equation.
c) A sample of 11 observations collected in a regression study on two variables, x(independent variable) and y(dependent variable). The sample resulted in the following data.
SSR=76, SST=83, summation (x_i-xbar)2=25, summation (x_i-xbar)(y_i-ybar)=49.
Calculate the t test statistics to determine whether a statistically linear relationship exists between x and y.
d)
A sample of 8 observations collected in a regression study on two variables, x(independent variable) and y(dependent variable). The sample resulted in the following data.
SSR=73, SST=86
Calculate the F test statistics to determine whether a statistically linear relationship exists between x and y.
In: Statistics and Probability