Question

In: Statistics and Probability

Thirty-two 1-Liter specimens of water were drawn from the water supply for a city and the...

Thirty-two 1-Liter specimens of water were drawn from the water supply for a city and the concentration of lead in the specimen was measured. The average level of lead was 7.3 µg/Liter, and the standard deviation for the sample was 3.1 µg/Liter. Using a significance level of 0.05, do we have evidence the mean concentration of lead in the city’s water supply is less than 10 µg/Liter? Find:

The t critical value ?

If the true mean equals the null mean the probability the test statistic value will be less than the t critical value is ?

Our test result cannot be

(a) A correct decision

(b) a Type I error

(c) a Type II error

IF given below are some possible values for the true mean (given in units of µg/Liter). Which value will give the LARGEST probability of a Type II error?

(a) 7.2 (b) 8.6 (c) 9.4 (d) 11.3

IF given below are some possible values for the true mean (given in units of µg/Liter). Which value will give the SMALLEST probability of a Type II error?

(a) 7.2 (b) 8.6 (c) 9.4 (d) 11.3

Solutions

Expert Solution


Related Solutions

1. Concerning the water supply system and structure from the two different water companies, explain the...
1. Concerning the water supply system and structure from the two different water companies, explain the soundness of the research approach. Is this descriptive or analytic epidemiologic research design?
A 1 liter sample of a lake water has an Alk of .2 meq/liter and contains...
A 1 liter sample of a lake water has an Alk of .2 meq/liter and contains .18 mM of carbonate species. a. what is the pH ? b. how much does pH change when 5 x 10 to the -5 power mol of hydrochloric acid are added ?
two cylindrical specimens A and B of a soil were loaded as follows. Both specimen were...
two cylindrical specimens A and B of a soil were loaded as follows. Both specimen were isotropically loaded by a stress of 200 kpa under drained conditions. Subsequently, the radial stress applied on specimen A was held constant and the axial stress was incrementally increased to 440 kpa under undrained conditions. The axial stress on specimen B was held constant and the radial stress was incrementally reduced to 50 kpa under drained conditions. plot the total and effective stress paths...
Contaminated water: In a sample of 42 water specimens taken from a construction site, 26 contained...
Contaminated water: In a sample of 42 water specimens taken from a construction site, 26 contained detectable levels of lead. Part 1 of 3 Your Answer is correct (a) Construct a 90% confidence interval for the proportion of water specimens that contain detectable levels of lead. Round the answer to at least three decimal places. A 90% confidence interval for the proportion of water specimens that contain detectable levels of lead is 0.497<<p0.743 . Part: 1 / 3 1 of...
Assuming a cost of AED 1.5/Liter to pump and distribute water in a municipal supply system...
Assuming a cost of AED 1.5/Liter to pump and distribute water in a municipal supply system that loses (P) of its water because of leaks, how much money is wasted annually for a city of (X) million people with a per capita demand of 300 Liters/day? where, X = 21.0 millions P = 2%
Two random samples of 40 students were drawn independently from two populations of students. Assume their...
Two random samples of 40 students were drawn independently from two populations of students. Assume their aptitude tests are normally distributed (total points = 100). The following statistics regarding their scores in an aptitude test were obtained: xbar1= 76, s1 = 8, xbar2 = 72, and s2 = 6.5. Test at the 5% significance level to determine whether we can infer that the two population means differ. (Note: You cannot necessarily assume that the populations have the same variances). Please...
Two random samples were drawn from members of the U.S. Congress. One sample was taken from...
Two random samples were drawn from members of the U.S. Congress. One sample was taken from members who are Democrats and the other from members who are Republicans. For each sample, the number of dollars spent on federal projects in each congressperson's home district was recorded. Dollars Spent on Federal Projects in Home Districts Party Less than 5 Billion 5 to 10 Billion More than 10 billion Row Total Democratic 6 16 23 45 Republican 11 17 19 47 Column...
Two random samples were drawn from members of the U.S. Congress. One sample was taken from...
Two random samples were drawn from members of the U.S. Congress. One sample was taken from members who are Democrats and the other from members who are Republicans. For each sample, the number of dollars spent on federal projects in each congressperson's home district was recorded. Dollars Spent on Federal Projects in Home Districts Party Less than 5 Billion 5 to 10 Billion More than 10 billion Row Total Democratic 9 11 25 45 Republican 11 19 17 47 Column...
1. The following 10 numbers were drawn from a population. Is it likely that these numbers...
1. The following 10 numbers were drawn from a population. Is it likely that these numbers came from a population with a mean of 13? Evaluate with a two-tailed test at p < .05. 5, 7, 7, 10, 10, 10, 11, 12, 12, 13 a. State both in words, and then symbolically what your H1 and H0 would be. b. What is your df? What is your critical t? c. Calculate t d. Based on the above information, would you...
1.Water samples were taken from water used for cooling as it was being discharged from a...
1.Water samples were taken from water used for cooling as it was being discharged from a power plant into a river. It has been determined that as long as the mean temperature of the discharged water is at most 150 F, there will be no negative impact on the river's ecosystem. To investigate whether a plant is in compliance with regulations that prohibit a mean discharge water temperature above 150 F, researchers took 50 water samples at randomly selected times...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT