What is the optimal time for a scuba diver to be on the bottom of the ocean? That depends on the depth of the dive. The U.S Navy has done a lot of research on this topic. The Navy defines the "optimal time" to be the time at each depth for the best balance between length of work period and decompression time after surfacing. Let x = depth of dive in meters, and let y = optimal time in hours. A random sample of divers gave the following data. | x 12.1 2.48 26.3 1.98 38.3 51.3 20.5 22.7 32.2 1.68 1.03 0.75 2.38 2.20 (a) Find Ex, Ey, Ex?, Ey², Exy, and r. (Round r to three decimal places.) Ex= 203.4 Ey = 12.5 Ex2 = 312.382 x Ey2 = 6909.06 x Exy = 25.021 (b) Use a 1% level of significance to test the claim that p< 0. (Round your answers to two decimal places.) critical t

To illustrate the effects of driving under the influence (DUI) of alcohol, a police officer brought a DUI simulator to a local high school. Student reaction time in an emergency was measured with unimpaired vision and also while wearing a pair of special goggles to simulate the effects of alcohol on vision. For a random sample of nine teenagers, the time (in seconds) required to bring the vehicle to a stop from a speed of 60 miles per hour was recorded. Complete parts (a) and (b). Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers. Click the icon to view the data table. (a) Whether the student had unimpaired vision or wore goggles first was randomly selected. Why is this a good idea in designing the experiment? A. This is a good idea in designing the experiment because it controls for any "learning" that may occur in using the simulator. B. This is a good idea in designing the experiment because…

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 45 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that o = 7.60 ml/kg for the distribution of blood plasma. (a) Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.) lower limit upper limit margin of error (b) What conditions are necessary for your calculations? (Select all that apply.) n is large the distribution of weights is normal o is known the distribution of weights is uniform o is unknown (c) Interpret your results in the context of this problem. The probability that this interval contains the true average…

5. Oxygen demand is a term blologists use to describe the axygen needed by fish and other aquatic organisms for survval. The Environmental Protection Agency conducted a study of a wetland area in Marin County, Californla. In this wetland environment, the mean oxygen demand was u=9.9 mg/L, and a= 1.7 mg/L. (Reference: EPA Report 832-R- 93- 005). Let x be a random varlable that represents oxygen demand in this wetland environment. Assume x has a probability distribution that is approximately normal. a. An oxygen demand below 8 mg/L Indicates that some organisms In the wetland environment may be dying. What is the probability that the oxygen demand will fall below 8 mg/L? b. A high oxygen demand can also indicate trouble. An oxygen demand above 12 mg/L may indicate an overabundance of organisms that endanger some types of plant life. What is the probability that the oxygen demand will exceed 12 mg/L?

It is a well-known fact that 40% of college students LOVE taking Mathematics. A certain professor at WCC wanted to test to see if a majority of students at WCC LOVE taking Mathematics. To test this, the professor randomly samples 1000 students and finds that 515 of them LOVE taking Mathematics.At the 0.05 level of significance, does the above sample provide evidence to suggest a majority of students at WCC LOVE taking Mathematics? Step 1: Define the parameter & setup the testStep 2: State the Level of SignificanceStep 3: Find the value of the Test StatisticsStep 4: Find P-Value OR Find Critical ValueStep 5: State Conclusion and why

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 46 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that ? = 7.50 ml/kg for the distribution of blood plasma. d)Find the sample size necessary for a 99% confidence level with maximal margin of error E = 2.60 for the mean plasma volume in male firefighters. (Round up to the nearest whole number.) =__ male firefighters What price do farmers get for their watermelon crops? In the third week of July, a random sample of 45 farming regions gave a sample mean of x = $6.88 per 100 pounds of watermelon. Assume that ? is known to be $2.00 per 100 pounds. (a) Find a 90% confidence interval for the population mean price (per 100 pounds) that…

One tree in the study had a weight that exceeded its expected weight (according to the best fit curve) by more than that of any other tree. By how many tons did the trees actual weight exceed the expected weight for its height?

Access the significsnce of each of the variables in the attached table. For age, write out all of the steps for hypothesis testing. For the other variables, report a p-value and conclusion. Write out the interpretation of the hazards ratios for age and sex in words. What is the estimated hazard ratio for a 10-year increase in age?

Lecture(8.8): The amount of time people engage in physical  activity mat be related to health outcome. Those who report that they spend more than 15 hours are put into one while those who spend less 10 were put into another group. (Those who fall in between 10 and 15 were left out of the study); The reaearcher then ask the participants to wear a monitor for one month. The average time  in minutes is recorded and shown below . Is there any evidence that on average people who watch less than 10 hours    watching televsion spend more time on physical activity.?. Test the hypotheses at (alpha=0.05) using the 5 step procedure <10 hours       75        63      118      35           82 >15 hours      62         6        78       43            22    33

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 44 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that ? = 7.20 ml/kg for the distribution of blood plasma. (a) Find a 99% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Round your answers to two decimal places.)lower limit= upper limit= margin of error= (b) What conditions are necessary for your calculations? (Select all that apply.) the distribution of volumes is normal ? is known the distribution of volumes is uniform n is large ? is unknown c) Find the sample size necessary for a 99% confidence level with maximal margin of error E = 2.80 for the mean plasma…