A forester studying the effects of fertilization on certain pine forests in the Southeast is interested in estimating the average basal area of pine trees. In studying basal areas of similar trees for many years, he has discovered that these measurements (in square inches) are normally distributed with standard deviation approximately 5 square inches. If the forester samples n = 9 trees, find the probability that the sample mean will be within 4 square inches of the population mean. (Round your answer to four decimal places.) You may need to use the appropriate appendix table or technology to answer this question. Need Help? Read It

A forester studying the effects of fertilization on certain pine forests in the Southeast is interested in estimating the average basal area of pine trees. In studying basal areas of similar trees for many years, he has discovered that these measurements (in square inches) are normally distributed with standard deviation approximately 5 square inches. If the forester samples n = 9 trees, find the probability that the sample mean will be within 4 square inches of the population mean. (Round your answer to four decimal places.) You may need to use the appropriate appendix table or technology to answer this question. Need Help? Read It

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Question 4 The time taken by employees at Grace Floral shop to put a bouquet together has a normal distribution with mean 26.4 minutes and standard deviation .8 minutes. (i) Find the probability that an employee chosen at random takes between 24.6 and 27.8 minutes to put a bouquet together. (ii) 12% of employees take more than t minutes to put a bouquet together. (iii) Find the value of t.
Question 3 The average score of all sixth graders in school District A on a math aptitude exam is 75 with a standard deviation of 8.1. A random sample of 80 students in one school was taken. The mean score of these 100 students was 71. Does this indicate that the students of this school are significantly different in their mathematical abilities than the average student in the district? Use a 5% level of significance.
Question 3
Question three John and his friend were recently having a heated discussion about the number of men living in a western parish who possibly cared for children that are not biologically theirs during 2019. Assume that a survey of the parish’s population revealed that the average number of cases and the standard deviation was 5,000 and 6000 in 2019, respectively. John and his friend do not believe that the population average is correct. Assume that a survey based on a sample of the 800 people was conducted and found that the average number of cases in the western parish was 10,000 over the 12 months period. Conduct a hypothesis test, using a 5% significance level to determine if the average number of cases is actually higher based on the sample data.
Question 2Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with a mean of 6.5 inches and a standard deviation of 0.7 inches.a. In what range would you expect to find the middle 82% of most head breadths? (Round your answer to 2 decimal places.)b. If you were to draw samples of size 60 from this population, in what range would you expect to find the middle 82% of most averages for the breadths of male heads in the sample? (Round your answer to 2 decimal places.)
EXPERIMENT 1: A researcher believes that on average women weigh less today than during the renaissance period around the 15th to 16th centuries. To investigate this belief, a random sample of 41 adult wômen is chosen and their weights are recorded. The mean weight of the sample is 111 pounds with a standard deviation of 12.4 pounds. Based on historical records and paintings of women from the renaissance, it is determined that the average weight of an adult women from that period would have been about 115 pounds.
Solve question 1 last part b where the question states... Probability that the total amount of time required to make an oil change in all cars from the sample of 100 cars is more than 3500 minutes is________
A developmental psychologist is interested in studying how long babies gaze at a photograph of a human face. To test this question, she shows a picture to a sample of six babies and records the length of their gaze in seconds. The data are as follows: 12, 17, 18, 20, 20, 29. Calculate the mean, median, mode, range, variance and standard deviation for the sample.
Question #11
QUESTION 9 The length of an adult Great White Shark is normally distributed with a mean of 3.4 meters and a standard deviation of 0.5 meters. What is the probability that a randomly selected adult Great White is more than 4.7 meters long? Click Save and Submit to save and submit. Click Save All Answers to save all answers.
Example 4: The average cholesterol level for a random sample of 25 adult women is 263 units with a standard deviation of 43 units. From previous study, it is known that the population is normally distributed with a standard deviation of 40 units. Find a 90% C.I for the mean cholesterol level for all adult women in the population.
Solve question #9 for part D only.