Question

In: Statistics and Probability

A compound found in drinking water is said to be harmless if its recoverable amount in...

A compound found in drinking water is said to be harmless if its recoverable amount in the drinking water was 25ppm (or less). An independent organization investigate a source of drinking water and believe that the source does not comply with the standards.

a) Specify an error type I that might be done by this organization and effects of the action to be taken because doing the error.

b) Specify an error type II which may be done by this organization and action will be taken because doing the error.

Solutions

Expert Solution

Null Hypothesis(H0): 25 ppm (the source complies with the standards).

Alternative Hypothesis(H1): > 25 ppm (the source does not comply with the standards).

a)

Type I error is the rejection of a true null hypothesis. So, in this case, type I error is rejecting that the source complies with the standards when in fact the source complies with the standards.

Because of this error, the organization concludes that the source does not comply with the standards and so, it considers harmless drinking water as not harmless(or harmful).

b)

Type II error is failing to reject a false null hypothesis. In this case, type II error means failing to reject that the source complies with the standards when in fact the source does not comply with the standards.

Because of this error, the organization concludes that the source complies with the standards and so, it considers harmful drinking water as harmless so that the people continue to drink that harmful water which is dangerous.

Thus, in this case, type II error is more serious than type I error.


Related Solutions

You wish to determine the amount of lead in a drinking water sample (500mL). It is...
You wish to determine the amount of lead in a drinking water sample (500mL). It is possible that sulfate in the sample (as well as other ions) will produce a matrix effect that will compromise the analysis, so you use a standard addition calibration method. You transfer 15 mL of your sample into each of five 50 mL volumetric flasks. You add the following volumes of a 5 ppm lead standard to the 5 flasks : 0, 5, 10, 15,...
Beast Ltd has identified recoverable amount on one of its CGUs to be $470,000. Land has...
Beast Ltd has identified recoverable amount on one of its CGUs to be $470,000. Land has a fair value (less costs to sell) of $204,000. All assets are measured using the cost model. • The CGU consists of the following assets (stated at current carrying amounts): • Cash 22,000 • Accounts receivable 55,000 Allowance Bad debts (15,000) • Factory 195,000 Accumulated dep. (45,000) • Equipment 90,000 Accumulated dep. (10,000) • Land 210,000 • Goodwill 20,000 Required: Calculate any impairment loss...
46. Which of the following are recoverable if a contract is found to be legally void?...
46. Which of the following are recoverable if a contract is found to be legally void? Answers: A. Consideration already paid B. Damages for breach C. Both A and B D. Neither A or B 47. Contracts where the principal objective is illegal are generally considered voidable. Answers: True False 48. Ignorance of fact or special regulation is an exception to the general rule that illegal contracts are void applies only if no immoral behavior or threat to public welfare...
A city is considering a reservoir water as its new drinking water source. As a result,...
A city is considering a reservoir water as its new drinking water source. As a result, the city council wants to know how good the reservoir water is to serve this potential purpose. Assume you are the chief engineer of the city utilities; please provide a list of water quality parameters need to be tested and the corresponding testing methods.
Periodically, the county Water Department tests the drinking water at its water distribution center. The lead...
Periodically, the county Water Department tests the drinking water at its water distribution center. The lead levels (parts per billion or ppb) for 10 recent samples are shown below. 2016182228132415261120161822281324152611 Officials want to determine if the median lead level exceeds the EPA action level of 15 ppb. They are unwilling to make any assumptions about the distribution of lead levels. Help them by conducting an appropriate distribution-free test. (1)    The observed value of the test statistic is     (2)    The p-value is (to...
Trace metals found in wells affect the taste of drinking water, and high concentrations can pose...
Trace metals found in wells affect the taste of drinking water, and high concentrations can pose a health risk. Researchers measured the concentration of zinc (in milligrams/liter) near the top and the bottom of 7 randomly selected wells in a large region. The data are provided in the following table. Construct and interpret a 90% confidence interval for the true mean difference (Bottom – Top) in the zinc concentrations of the wells in this region. well 1 2 3 4...
. It is often said that “water seeks its level.” Explain
. It is often said that “water seeks its level.” Explain
1. Samples of drinking water were analyzed for lead contamination. Analysis of the drinking water showed...
1. Samples of drinking water were analyzed for lead contamination. Analysis of the drinking water showed a lead concentration of 12.54 ppb. Analysis of a sample of the same drinking water spiked with 20.00 ppb lead gave a concentration of 29.63 ppb. Calculate the spike recovery. Is the method sufficiently accurate? 2. A chemical technician wants to verify the precision of an analytical procedure used to determine citric acid concentration in orange juice. She obtains 10.00 mL of a particular...
research on Lead on drinking water and toys
research on Lead on drinking water and toys
A hydrated nickel chloride compound was found to contain 24.69% Ni, 29.83% Cl, and 45.48% water....
A hydrated nickel chloride compound was found to contain 24.69% Ni, 29.83% Cl, and 45.48% water. Determine the empirical formula of this hydrated compound
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT