Purchase Solution

Statistics: What is the 95 percent interval for the population mean of trucks on I-475?

Not what you're looking for?

Ask Custom Question

The mean weight of trucks traveling on a particular section of I-475 is not known. A state highway inspector needs an estimate of the mean. He selects a random sample of 49 trucks passing the weighing station and finds the mean is 15.8 tons, with a standard deviation of the sample of 3.8 tons. What is the 95 percent interval for the population mean?

14.7 and 16.9

13.2 and 17.6

10.0 and 20.0

16.1 and 18.1

Purchase this Solution
Solution Summary

The detailed solution shows all the calculations to arrive at the answer.

Solution Preview

The correct answer is "14.7 and 16.9"

For samples larger than 30, the distribution of the sample mean can be considered to be approximately normal, with mean equal to the observed sample ...

Purchase this Solution
Free BrainMass Quizzes
Know Your Statistical Concepts

Each question is a choice-summary multiple choice question that presents you with a statistical concept and then 4 numbered statements. You must decide which (if any) of the numbered statements is/are true as they relate to the statistical concept.

Measures of Central Tendency

Tests knowledge of the three main measures of central tendency, including some simple calculation questions.

Measures of Central Tendency

This quiz evaluates the students understanding of the measures of central tendency seen in statistics. This quiz is specifically designed to incorporate the measures of central tendency as they relate to psychological research.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

View More Free Quizzes
Related BrainMass Solutions

  • Confidence Interval interpretation with reasoning

    A 95% confidence interval for the mean cost is constructed and found to be $253 to $320. He reasons that this interval contains the mean operating cost for the fleet of delivery trucks since the sample mean is contained in the interval. a.

  • Findind confidence interval for true mean

    201699 Finding confidence interval for true mean Find the confidence interval for the true mean assuming that each sample is from a normal population and we know the standard deviation: The given data is: Xbar = 14 Standard deviation = 4 N=5 Use

  • Students t test

    The sample mean is 40, and the sample standard deviation is 5. Determine the 95 percent confidence interval for the population mean. 5. Merrill Lynch Securities and Health Care Retirement, Inc., are two large employers in downtown Toledo, Ohio.

  • Normal Probability, Hypothesis Testing & Confidence Interval

    Assuming a normal population distribution, construct a 95 percent confidence interval for the population mean weight. 3. Of a random sample of 600 trucks at a bridge, 120 had bad signal lights.

  • Statistics - Confidence Intervals for ACT Scores

    Estimate the mean mathematics ACT score for all statistics students at this college. Give the 95 percent confidence interval. Solution: This is a 95 percent confidence interval for the population mean.

  • 90 percent confidence intervals of surgical procedures

    Solution: 95 percent confidence interval for the percentage of trucks that had bad signal lights is 3.

  • Manager's sample of 25 delivery trucks. Confidence interval

    A 95% confidence interval for the mean cost is constructed and found to be $253 to $320. He reasons that this interval contains the mean operating cost for the fleet of delivery trucks since the sample mean is contained in the interval. a.

  • Miscellaneus Statistics Questions

    Their accounts are reviewed for total account valuation, which showed a mean of $34,900, with a sample standard deviation of $8,300. What is a 95 percent confidence interval for the mean account valuation of the population of customers?

  • Confidence interval for mean and proportion

    The confidence interval: 5.06 < sigma2 < 23.33 is for the population variance based on the following sample statistics: n = 25, x-bar = 41.2, and s = 3.1 What is the degree of confidence?

View More Related Solutions