Bob Nale is the owner of Nale’s Quick Fill. Bob would like to estimate the mean number of gallons of gasoline sold to his customers. Assume the number of gallons sold follows the normal distribution with a population standard deviation of 1.90 gallons. From his records, he selects a random sample of 45 sales and finds the mean number of gallons sold is 5.70. a. What is the point estimate of the population mean? (Round your answer to 2 decimal places.) Point estimate b. Determine a 90% confidence interval for the population mean. (Use z Distribution Table.) (Round your answers to 2 decimal places.) Confidence interval and
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.
Bob Nale is the owner of Nale’s Quick Fill. Bob would like to estimate the mean number of gallons of gasoline sold to his customers. Assume the number of gallons sold follows the
a. |
What is the point estimate of the population mean? (Round your answer to 2 decimal places.) |
Point estimate |
b. |
Determine a 90% confidence interval for the population mean. (Use z Distribution Table.) (Round your answers to 2 decimal places.) |
Confidence interval | and |
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