# Question

The campus at Joliet Junior College has a lake.A student used a Secchi disk to measure the clarity of the lake’s water by lowering the disk into the water and measuring the distance below the water surface at which the disk is no longer visible. The following measurements (in inches) were taken on the lake at various points in time over the

course of a year.

(a) Use the data to compute a point estimate for the population mean and population standard deviation.

(b) Because the sample size is small, we must verify that the data are normally distributed and do not contain any outliers. The ﬁgures on the next page show the normal probability plot and boxplot. Are the conditions for constructing a conﬁdence interval about m satisﬁed?

(c) Construct a 95% conﬁdence interval for the mean Secchi disk measurement. Interpret this interval.

(d) Construct a 99% conﬁdence interval for the mean Secchi disk measurement. Interpret this interval.

course of a year.

(a) Use the data to compute a point estimate for the population mean and population standard deviation.

(b) Because the sample size is small, we must verify that the data are normally distributed and do not contain any outliers. The ﬁgures on the next page show the normal probability plot and boxplot. Are the conditions for constructing a conﬁdence interval about m satisﬁed?

(c) Construct a 95% conﬁdence interval for the mean Secchi disk measurement. Interpret this interval.

(d) Construct a 99% conﬁdence interval for the mean Secchi disk measurement. Interpret this interval.

## Answer to relevant Questions

From a random sample of 1201 Americans, it was discovered that 1139 of them lived in neighborhoods with acceptable levels of carbon monoxide. Source: Environmental Protection Agency. (a) Obtain a point estimate for the ...Determine the point estimate of the population proportion, the margin of error for each conﬁdence interval, and the number of individuals in the sample with the speciﬁed characteristic, x, for the sample size ...In response to the Great Depression, Franklin D. Roosevelt enacted many New Deal policies. One such policy was the enactment of the National Recovery Administration (NRA), which forced business to agree to wages and prices ...One question on the Sullivan Statistics Survey is “Would you be willing to pay higher taxes if the tax revenue went directly toward deﬁcit reduction?” Treat the survey respondents as a simple random sample of adult ...In a Gallup Poll conducted October 2010,44% of the people polled answered “more strict” to the following question:“Do you feel that the laws covering the sale of ﬁrearms should be made more strict, less strict, or ...Post your question

0