Phosphorous is a chemical that is found in many household cleaning products. Unfortunately, phosphorous also finds its way into surface water, where it can harm fish, plants, and other wildlife. Two methods of phosphorous reduction are being studied. At a random sample of 7 locations, both methods were used and the total phosphorous reduction (mg/L) was recorded. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value a small amount and thereby produce a slightly more "conservative" answer. Things that are labelled i underneath a b c, etc are all part of that part.

Researchers were interested in assessing whether stress levels are different at the beginning of the semester compared to finals week. To test this, stress was measured in 5 students at the start of the semester and then again at the end of the semester during finals week.    Participant Stress 1 Stress 2 1 22 22 2 32 34 3 24 25 4 28 30 5 26 29   Then H0: μ2 - μ1 ≠ 0, true or false?

NASA is conducting an experiment to find out the fraction of people who black out at G forces greater than 6. Step 1 of 2: Suppose a sample of 525 people is drawn. Of these people, 215 passed out at G forces greater than 6. Using the data, estimate the proportion of people who pass out at more than 6 Gs. Enter your answer as a fraction or a decimal number rounded to three decimal places.

I am having trouble solving this problem.  Can you please provide me with some help?  Thank you.  I appreciate it. Almonte. Inc., a maker of low-priced hair care products, claims that its hair spray lasts as long as the industry leader's higher-priced product.  You take a sample of 60 applications of Almonte's hair spray and 60 applications of the leading hair spray.  Results: On average, the Almonte applications held for 12.7 hours with a standard deviation of 1.4 hours.  On average, the leading hair spray lasted 11.8 hours with a standard deviation of 1.8 hours.  Set up a hypothesis test to test whether the difference in sample means is statistically significant.  Use a significance level of 1%.  Report and explain your conclusion.

Scientists did a study to see whether a new fuel additive had any effect on gas mileage (mpg). Seven identical cars were driven for 1 week with normal gas/no additive, and then driven the next week using gas with the additive. The miles-per-gallon was recorded for each vehicle. Please use the appropriate t-test and do the calculations requested below and fill in the blanks.    No additive      Additive           D         D2     16                    19                3           9     13                    16                3           9     15                    14               -1          1     17                    17                0          0     20                    24                4         16     26                    28                2          4     25                    28                3          9                                          ∑D=14   ∑D2= 48 For this study, the sample size n =  and the mean difference MD = .  The SSD =  , the variance s2D = , the…

Please answer part B and C. Thank You

Rivers in North Carolina contain small concentrations of mercury that can accumulate in fish over their lifetimes. The concentration of mercury in fish tissue can be obtained by catching fish and sending samples to a lab for analysis. A study was conducted on fish from the Waccamaw and Lumber Rivers to investigate mercury levels in tissues of largemouth bass. At several stations along each river a group of fish were caught, weighed and measured; in addition a filet from each fish was sent to a lab so that the tissue concentration of mercury could be determined. In all, 171 fish were caught at 15 different research stations along the Waccamaw and Lumber Rivers. Data from fish caught at one of these stations is shown in the followinng table: length weight 1616 47.0 48.7 1862 2855 55.7 45.2 1199 1320 44.7 1225 43.8 870 38.5 1455 45.8 1220 44.0 1033 40.4 Compute the correlation between length and weight for these fish. (Assume the correlation conditions have been satisfied and round your…

Interpret effect size t(30)=1.12, p=.34, n2=.001 small, medium, or large

A researcher would like to examine how the chemical tryptophan, contained in foods such as turkey, can affect mental alertness.  A sample of n = 9 college students is obtained and each student’s performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roast turkey.  The average score dropped by M = 14 points after the meal with SS = 1152 for the difference scores. A. Is there is significant difference in performance before eating versus after eating?  Use a                two-tailed test with α = .05.             SMD = ___________________________             tcritical =     ________________________             tcalculated =    ________________________                  Decision = _______________________             B. Compute r2 to measure the size of the effect.             r2  = _____________________________   C. Write a sentence demonstrating how the outcome of the test and the measure of effect                size would…

Scientists are looking at the effects of global warming on clutches of sea turtle hatchlings in different parts of the world. The data below has been collected: 1.Temperature of Incubation (in Kelvin) 2. Gender Group of Hatchling Clutch (0=0% male; 1= greater than 0% but less than or equal to 10% male; 2= greater than 10% but less than 20% male; 3= greater than 20% but less than or equal to 30% male and so on) 3. Number of hatched eggs 4. number of unhatched eggs 5. Location of Turtles (0=west North America; 1= west South America; 2= tropical regions of Pacific; 3= northwestern Atlantic; 4= Indian Ocean  Which of the above variables are measured using a nominal scale, ordinal scale and ratio scale. (An answer can be none of variables)   thank you