Periodically, a town water department tests the the drinking water of homeowners for contaminants such as lead. The lead levels in water specimens collected for a sample of 10 residents of the town had a mean of 3.2 mg/L and a standard deviation of 2.6 mg/L. Complete parts a through c. a. Construct a 95% confidence interval for the mean lead level in water specimens from the town. OD (Round to three decimal places as needed.) b. Interpret the interval in terms of this application. Choose the correct answer below. O A. The water department can be 95% confident that the mean lead level in drinking water for all residents in the town is 3.2 mg/L. O B. The water department can be 5% confident that the mean lead level in drinking water for all residents in the town is within this interval. Oc. The water department can be 95% confident that the mean lead level in drinking water for all residents in the town is within this interval. O D. The water department is confident that 95% of the mean lead level in drinking water for all residents in the town is described by this interval. O E. The water department can be 95% confident that the mean lead level in drinking water for all residents the town is outside this interval. c. The phrase "95% confidence interval" means that if many intervals were constructed using the same methods and with the same sample size then % of these intervals would contain the true value of which of the following choices? OD. Population O A. Sample mean O B. Standard error Oc. Standard deviation mean
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
Mean, Median, Mode
It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
Please provide an explanation for each part.
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