Question

In: Statistics and Probability

The EPA wants to know the daily level of pollutant discharge in the manufacturing district in...

The EPA wants to know the daily level of pollutant discharge in the manufacturing district in Pittsburgh for eight weeks (i.e. 56 days). The monitoring equipment reveals that the mean daily discharge per factory (calculated as total areal discharge divided by total areal factories) is 30.2 tons with a standard deviation of 9.1 tons. Construct a confidence interval for the true population mean of pollutant discharge using a 99% level of confidence.

Solutions

Expert Solution

Given :

as the population standard deviation is unknown (not given) , we need to use t-interval .

The confidence interval formula for population mean is ,

We have to find the 99% confidence interval ,

so c = 0.99

Degrees of freedom = n - 1 = 56-1 = 55

df = 55

Using excel function ,   =TINV( , df )

=TINV( 0.01 , 55 )

=2.668

Now plug the values in the formula ,

Therefore a confidence interval for the true population mean of pollutant discharge using a 99% level of confidence is ( 26.9556 , 33.4444 )

orchestra answered 2 years ago
Next > < Previous

Related Solutions

The EPA limit on the allowable discharge of suspended solids into rivers and streams is 60...
The EPA limit on the allowable discharge of suspended solids into rivers and streams is 60 milligrams per liter (mg/l) per day. A study of water samples selected from the discharge at a phosphate mine shows that over a long period, the mean daily discharge of suspended solids is 48 mg/l, but day-to-day discharge readings are variable. State inspectors measured the discharge rates of suspended solids for n = 20 days and found s2 = 32 (mg/l)2. Find a 90%...
The EPA limit on the allowable discharge of suspended solids into rivers and streams is 60...
The EPA limit on the allowable discharge of suspended solids into rivers and streams is 60 milligrams per liter (mg/l) per day. A study of water samples selected from the discharge at a phosphate mine shows that over a long period, the mean daily discharge of suspended solids is 48 mg/l, but day-to-day discharge readings are variable. State inspectors measured the discharge rates of suspended solids for n = 20 days and found s2 = 32 (mg/l)2. Find a 90%...
The superintendent of the Middletown school district wants to know which of the districts three schools...
The superintendent of the Middletown school district wants to know which of the districts three schools has the lowest rate of parent satisfaction. He distributes a survey to 1,000 parents in each district which asks if the parent is satisfied with their child’s school, and all of these parents respond. Here are the results school school A school B school C total not satisfied 248 250 300 798 satisfied 752 750 700 2202 Total 1000 1000 1000 3000 a. Percentage...
A company that manufactures electronic components wants to know the mean discharge time of one particular...
A company that manufactures electronic components wants to know the mean discharge time of one particular type of capacitor that it makes. In order to estimate this value, they randomly select 100 capacitors and measure how long they take to discharge. The mean of this sample was 7.25 seconds with a standard deviation of 0.15 seconds. Assuming that this distribution is normal, construct a 99% confidence interval to estimate the mean discharge time for all capacitors of this type. Since...
EPA regulates the level of CO2 emissions. Recently, the EPA began applying an automated control chart...
EPA regulates the level of CO2 emissions. Recently, the EPA began applying an automated control chart methodology to detect undermeasurement of emissions data. The three daily samples of CO2 levels for each of 15 days are shown in the below table. a. Construct two control charts for the daily average and variation of CO2 levels. b. Based on the control chart, describe the behavior of the measurement process. day CO2 Level 1 12.9 12.1 13.8 2 13.2 13.2 12.7 3...
A restaurant chain in Ontario wants to know the level of satisfaction of their customers. From...
A restaurant chain in Ontario wants to know the level of satisfaction of their customers. From each of Toronto and Ottawa, a random sample of 14 customers was selected and asked to rate their dining experience on a scale from 1 to 10 (with 1 being not satisfied at all, 10 being extremely satisfied). A total of 28 scores was collected. Below is a summary of the data: City Toronto Ottawa Sample Mean 4.3611 5.9444 Sample std. 1.1401 2.4254 #...
A researcher suspects that the mean pollutant level in a region is higher than the state...
A researcher suspects that the mean pollutant level in a region is higher than the state average of 4.3 grams/cubic liter. Data are collected; from 56 samples, the mean is found to be 5.4, with a standard deviation of 5.0. Test the null hypothesis that the true mean in the region is 4.3, against the alternative that it is higher. State the null and alternative hypotheses, give the critical value, find the test statistic, make a decision, and give the...
5. A researcher suspects that the mean pollutant level in a region is higher than the...
5. A researcher suspects that the mean pollutant level in a region is higher than the state average of 4.3 grams/cubic liter. Data are collected; from 56 samples, the mean is found to be 5.4, with a standard deviation of 5.0. Test the null hypothesis that the true mean in the region is 4.3, against the alternative that it is higher. State the null and alternative hypotheses, give the critical value, find the test statistic, make a decision, and give...
5. A researcher suspects that the mean pollutant level in a region is higher than the...
5. A researcher suspects that the mean pollutant level in a region is higher than the state average of 4.3 grams/cubic liter. Data are collected; from 56 samples, the mean is found to be 5.4, with a standard deviation of 5.0. Test the null hypothesis that the true mean in the region is 4.3, against the alternative that it is higher. State the null and alternative hypotheses, give the critical value, find the test statistic, make a decision, and give...
Assume that lake Hefner has volume billion cubic meters with initial pollutant concentration of, The daily...
Assume that lake Hefner has volume billion cubic meters with initial pollutant concentration of, The daily inflow of water is million cubic meters with a pollutant concentration of, Assume that the water is well mixed in the lake and the water flow out from the lake at the same rate. (a) How long will it take to reduce pollutant concentration in the lake? (b) What will be the pollutant concentration in the lake eventually?
ADVERTISEMENT
Subjects
ADVERTISEMENT
Latest Questions
ADVERTISEMENT