Discuss the following problems:
1. Explain how you know the data in any research you are doing is valid.
2. Explain how you know the data in any research you are doing is reliable.
3. What are the fundamentals you must have to have data is gotten following scientific sampling procedures
4. Using the data below, make a histogram, box plot, compute the mean, median, mode and standard deviation
| City and State |
Crime |
| Albuquerque, NM |
8515 |
| Anaheim, CA |
2827 |
| Anchorage, AK |
4370 |
| Arlington, TX |
5615 |
| Atlanta, GA |
10759 |
| Aurora, CO |
5079 |
| Austin, TX |
6406 |
| Birmingham, AL |
7030 |
| Boston, MA |
4986 |
| Buffalo, NY |
5791 |
| Charlotte, NC |
7484 |
| Chicago, IL |
6333 |
| Cincinnati, OH |
5694 |
| Cleveland, OH |
5528 |
| Colorado Springs, CO |
4665 |
| Columbus, OH |
8247 |
| Corpus Christi, TX |
6266 |
| Dallas, TX |
8201 |
| Denver, CO |
4685 |
| Detroit, MI |
8163 |
| El Paso, TX |
5106 |
| Fort Worth, TX |
6636 |
| Fresno, CA |
6145 |
| Honolulu, HI |
4671 |
| Houston., TX |
6084 |
| Indianapolis, IN |
4306 |
| Jacksonville, FL |
6118 |
| Kansas City, MO |
9882 |
| Las Vegas, NV |
4520 |
| Lexington, KY |
5315 |
| Long Beach, CA |
3407 |
| Los Angeles, CA |
3306 |
| Louisville, KY |
5102 |
| Memphis, TN |
6958 |
| Mesa, AZ |
5590 |
| Miami, FL |
8619 |
| Milwaukee, WI |
6886 |
| Minneapolis, MN |
7247 |
| Nashville, TN |
7276 |
| New Orleans, LA |
6404 |
| New York, NY |
2968 |
| Newark, NJ |
6068 |
| Oakland, CA |
6820 |
| Oklahoma City, OK |
8464 |
| Omaha, NE |
5809 |
| Philadelphia, PA |
5687 |
| Phoenix, AZ |
6888 |
| Pittsburgh, PA |
5246 |
| Portland, OR |
6897 |
| Raleigh, NC |
6327 |
| Riverside, CA |
3610 |
| Sacramento, CA |
5859 |
| San Antonio, TX |
6232 |
| San Diego, CA |
3405 |
| San Francisco, CA |
4859 |
| San Jose, CA |
2363 |
| Santa Ana, CA |
3008 |
| Seattle, WA |
8397 |
| St. Louis, MO |
11765 |
| St. Paul, MN |
6215 |
| Stockton, CA |
5638 |
| Tampa, FL |
8675 |
| Toledo, OH |
6721 |
| Tucson, AZ |
8079 |
| Tulsa, OK |
6234 |
| Virginia Beach, VA |
3438 |
| Washington, DC |
6434 |
| Wichita, KS |
c |
5. In child custody case, about 70% of the fathers win the case is they contest it. IN the next thee custody cases what is the probability that all three win
6. SOB's systolic blood pressure is a random variable with a mean of 145 mmHG and a standard deviation of 20mmHG. If the SOB's blood pressure is taken at a randomly chosen moment what is the probability it will be below 135? What is the probability it will be over 175?
7. Find the required sample size to estimate the mean starting salary for a new CEO with a 95% confidence, assuming the standard deviation is $7,500 with an error of $2,000. Assume the population N is 1,250,000.
8. 95% of Popcorn kernels take between 100 and 200 seconds to pop. What sample size (number of kernels) would be needed to estimate the true mean seconds to pop with and error of 5 seconds and 95% confidence level?
9. A sample of 20 pages was taken from the 2,000 page phone directory. On each page, the mean area devoted to display ads was shown - see data below. Construct a 95% confidence interval for the true mean
|
| Display Ads |
| 0 |
| 260 |
| 356 |
| 403 |
| 536 |
| 0 |
| 268 |
| 369 |
| 428 |
| 536 |
| 130 |
| 268 |
| 396 |
| 469 |
| 536 |
| 162 |
| 338 |
| 403 |
| 536 |
| 536 |
10. Stores are not supposed to sell cigarettes to teenagers. Of 320 stores checked, 82 stores sold cigarettes to teens. Is the goal being achieved is to reduce the % of stores selling cigarettes to under 20%. (1) Do a hypothesis test to reject or fail to reject the Ho and (2) construct a 95% confidence interval to determine the true percent of stores who allow teems to purchase cigarettes.
11. The mean number of arrivals at Chicago O'Hare is 195 flights per hour. The historical standard deviation of flight arrivals at O'Hare is 13. Using the data below, set up a hypothesis test to se if there has been an increase in arrivals. Would you arrive at a different decsion if Alpha were .01?
| Flights |
| 210 |
| 215 |
| 200 |
| 189 |
| 200 |
| 213 |
| 202 |
| 181 |
| 197 |
| 199 |
| 193 |
| 209 |
| 215 |
| 192 |
| 179 |
| 196 |
| 225 |
| 199 |
| 196 |
| 210 |
| 199 |
| 188 |
| 174 |
| 176 |
| 202 |
| 195 |
| 195 |
| 208 |
| 222 |
| 221 |
12. One group of accounting students took an online course, The second groups of students took the same accounting course in a traditional classroom. At Alpha of .10 is there any difference in the results. Find p-value and interpret it
|
Online Students |
|
Classroom |
| Mean |
9.1 |
|
10.3 |
| Sample Std.dev. |
2.4 |
|
2.5 |
| N count |
20 |
|
20 |
13. In a lottery each digit is supposed to have the same probability of occurrence. The table below shows the occurrence of each digit of 89 consecutive daily drawings. The Research questions is: at the .01 Alpha can you reject the Ho that the digits are from a uniform population.
|
Digit |
Frequency |
|
0 |
39 |
|
1 |
27 |
|
2 |
35 |
|
3 |
39 |
|
4 |
35 |
|
5 |
35 |
|
6 |
27 |
|
7 |
42 |
|
8 |
36 |
|
9 |
41 |
|
Total |
356 |
14. A sample of 100 mortgages approved during the course of a year showed that 31 were issued to single-earner family or individual. The historical average is 25%. Has the percentage of single-earned or individual mortgages risen? Test using Alpha .05.