Answered: Suppose that an accounting firm does a…

MATLAB: An Introduction with Applications

6th Edition

ISBN:9781119256830

Author:Amos Gilat

Publisher:Amos Gilat

Chapter1: Starting With Matlab

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Question

Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 100 people. The sample mean is 22.4 hours. There is a known population standard deviation of 6.4 hours. The population distribution is assumed to be normal.

NOTE: If you are using a Student's t-distribution, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

1. In words, define the random variables X and X

- X is the number of tax forms that an accounting firm completes, and X is the mean number of tax forms that an accounting firm completes.

-X is the time needed to complete one person's tax forms, and X is the mean time needed to complete tax forms from a sample of 100 customers.

-X is the number of tax forms that an accounting firm completes, and X is the mean number of tax forms that an accounting firm completes.

2. If the firm did another survey, kept the error bound the same, and only surveyed 49 people, what would happen to the level of confidence? Why?

-The level of confidence would be larger because we have collected a smaller sample, obtaining less accurate information.

-The level of confidence would be smaller because we have collected a smaller sample, obtaining less accurate information.

-There would be no change.

3. Suppose that the firm decided that it needed to be at least 96% confident of the population mean length of time to within one hour. How would the number of people the firm surveys change? Why?

-The number of people surveyed would decrease because more accurate information requires a smaller sample.

-The number of people surveyed would increase because more accurate information requires a larger sample.

-There would be no change.

Definition Definition Measure of central tendency that is the average of a given data set. The mean value is evaluated as the quotient of the sum of all observations by the sample size. The mean, in contrast to a median, is affected by extreme values. Very large or very small values can distract the mean from the center of the data. Arithmetic mean: The most common type of mean is the arithmetic mean. It is evaluated using the formula: μ = 1 N ∑ i = 1 N x i Other types of means are the geometric mean, logarithmic mean, and harmonic mean. Geometric mean: The nth root of the product of n observations from a data set is defined as the geometric mean of the set: G = x 1 x 2 ... x n n Logarithmic mean: The difference of the natural logarithms of the two numbers, divided by the difference between the numbers is the logarithmic mean of the two numbers. The logarithmic mean is used particularly in heat transfer and mass transfer. ln x 2 − ln x 1 x 2 − x 1 Harmonic mean: The inverse of the arithmetic mean of the inverses of all the numbers in a data set is the harmonic mean of the data. 1 1 x 1 + 1 x 2 + ...

Expert Solution