The table below displays data from an experiment focused on nutrient addition and plant diversity. The explanatory variable is the response variable is Number of Number of Plot # Nutrients Added Plant Species 36 2 36 32 4 34 33 3 30 20 8 23 4 21 10 4 16

A test was conducted of two overnight mail delivery services. Two samples of identical deliveries were set up so that both delivery services were notified of the need for a delivery at the same time. The hours required to make each delivery follow. Do the data shown suggest a difference in the delivery times for the two services? Use a .05 level of significance for the test. Use Table 1 of Appendix B. Click on the datafile logo to reference the data. DATA file Service Delivery 1 2 24.5 26.0 28.0 21.0 18.0 36.0 25.0 21.0 24.0 26.0 31.0 28.0 25.5 32.0 20.0 19.5 28.0 29.0 22.0 23.5 29.5 30.0 What is the z-statistic? If required, round your answer to two decimal places. Enter negative values as negative number, if necessary. -.31 What is the p-value? If required, round your answer to two decimal places. .76 Conclude. 12345 7890:=

Trace metals in drinking water affect the flavor and an unusually high concentration can pose a health hazard. Ten pairs of data were taken measuring zinc concentration in bottom water and surface water of a water source. Zinc Location concentration in concentration in bottom water Zinc surface water 1 .430 .415 2 .266 .238 3 .567 .390 .531 .410 .707 .605 .716 .609 7 .651 .632 8 .589 .523 9 .469 .411 10 .723 .612 Do the data support that the zinc concentration is less on the surface than the bottom of the water source, at the a =.1 level of significance? a) Express the null and alternative hypotheses in symbolic form for this claim. Assume d = bottom - surface. Enter != for + . Ho: Pd Ha: Pd b) What is the significance level? c) What is the test statistic? Round to 3 decimal places. d) What is the p-value? Round to 4 decimal places. p =

Here are data from an experiment studying the effect of age on creativity scores:     Age 4 Age 6 Age 8 Age 10 3 9 9 7 5 11 12 7 7 14 9 6 4 10 8 4 3 10 9 5     Compute Fobt and create an ANOVA summary table. What do you conclude about Fobt? Perform post hoc comparisons if appropriate. What should you conclude about this relationship? How important is age in determining creativity scores?

An experiment was conducted to compare the alcohol content of soy sauce on two different production lines. Production was monitored eight times a day. The data are shown here. Production line 1 0.38 0.37 0.39 0.41 0.38 0.39 0.40 0.39 Production line 2 0.48 0.39 0.42 0.52 0.40 0.48 0.52 0.52   Assume both populations are normal. It is suspected that production line 1 is not producing as consistently as production line 2 in terms of alcohol content. Perform a hypothesis test to compare the population standard deviation of these two types of production lines. What is the value of the test statistic?

An experiment was conducted to compare the alcohol content of soy sauce on two different production lines. Production was monitored eight times a day. The data are shown here. Production line 1 0.38 0.37 0.39 0.41 0.38 0.39 0.40 0.39 Production line 2 0.48 0.39 0.42 0.52 0.40 0.48 0.52 0.52   Assume both populations are normal. It is suspected that production line 1 is not producing as consistently as production line 2 in terms of alcohol content. Using the 0.05 level of significance, can conclude that the population standard deviations for the alcohol content of these two types of production lines could be the same.

Factor V is a protein involved in the forming of blood clots. The higher the level of factor V, the faster the blood clots. A Blood Transfusions Service is interested in the effects of sterilization of blood plasma because factor V is unstable and may break down during sterilization. The table below gives measured levels of factor V in blood samples from nine donors. Both pre- and post-sterilization measurements are given for each person. Test whether the mean factor V levels are different post-sterilization. Run the test at a 5% level of significance. Give each of the following  1) the appropriate null and alternative hypotheses; 2) the appropriate test; 3) the decision rule; 4) the calculation of the test statistic; and 5) your conclusion including a comparison to alpha or the critical value. Factor V measurements Donor number Pre-Sterilization Post-Sterilization 1 1025 985 2 1060 1030 3 953 923 4 847 892 5 750 650 6 855 759…

Hoaglin, Mosteller, and Tukey (1983) presented data on blood levels of beta-endorphin as a function of stress. They took beta-endorphin levels for 19 patients 12 hours before surgery and again 10 minutes before surgery.  The data are presented below.  Does there appear to be a difference in the mean level of beta endorphins present?    Participant                   12 hours before           10 minutes before 1                                  10                                6.5 2                                  6.5                               14.0 3                                  8.0                               13.5 4                                  12                                18 5                                  5.0                               14.5 6                                  11.5                             9.0 7                                  5.0                               18.0 8                                  3.5                               42.0…

Below is a table of most of the variables in the dataset. For each variable listed, identify both the type of variable and the level of measurement (e.g., a student’s gender is categorical, nominal). variables type level of measurment exp     wks     bluecol     ind     south     smsa     married     sex     union     ed     black     wage     wage2       1. exp (years of full-time experience)2. wks (weeks worked)3. bluecol (whether the worker is a blue collar worker)4. ind (whether the worker works in a manufacturing industry)5. south (whether the worker resides in the south)6. smsa (whether the worker resides in a standard metropolitan statistical area)7. married (whether the worker is married)8. sex (male or female)9. union (whether the worker is part of a union)10. ed (years of education)11. black (whether the worker is black)12. lwage (gives the logarithm of the worker’s wage)13. wage (gives the worker’s wage this past year)14. wage2 (gives the…

A team of epidemiologists at the Mayo Clinic wanted to find whether there is an association between obesity and cardiovascular disease (CVD). They conducted a prospective cohort study following obese and non-obese individuals who were free of CVD at the beginning of study for five years. The investigators were also interested in assessing age as a potential confounder, effect modifier, or both. Use the data below to answer the accompanying questions.     CVD No CVD Total Obese 10 90 100 Not Obese 35 465 500 Total 45 555 600       CVD No CVD Total Obese 36 164 200 Not Obese 25 175 200 Total 61 339 400   1. Compute the appropriate measure of association for those who were less than age 50.  2. Compute the appropriate measure of association for those who were older or equal to age 50.  3. Compute the crude measure of association?  4. List three attributes that age must satisfy before it could…