Purchase Solution

Probabilities for Failing a Test

Not what you're looking for?

Ask Custom Question

A metropolitan school system consists of three school districts-norths, south, central. The north district contains 25% of all students, the south district contains 40%, and the central district contains 35%. A minimum-competency test was given to all students; 10% of the north district students failed, 15% of the south district students failed, and 5% of the central district students failed.
a) Develop a probability tree showing all marginal, conditional, and joint probabilities.
b) Develop a joint probability table.
c) What is the probability that a student selected at random failed the test?

Purchase this Solution
Solution Summary

This solution contains a probability tree that helps calculate the joint probabilities and marginal probabilities of students going to North, South or Central. It also calculates the probability that a student selected at random failed the test. All steps are shown with clear explanations.

Purchase this Solution
Free BrainMass Quizzes
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.

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.

Terms and Definitions for Statistics

This quiz covers basic terms and definitions of statistics.

View More Free Quizzes
Related BrainMass Solutions

  • One and Two-Sample Hypothesis Testing

    If we plot the probabilities of failing to reject H0 corresponding to various alternatives for μ (including the value specified by H0) and connect all the points by a smooth curve, we obtain the operating characteristic curve of the test criterion

  • Probablity

    The test for this drug is 90% accurate that is, the test will correctly identify a drug user as testing positive 90% of the time and will also correctly identify a non drug user as testing negative 90% of the time (that is: P(tests positive | user

  • Event diagrams, Poisson & exponential failure processes

    b) Assume the probability of hazard barrier B failing is 0.25. The probabilities of barriers A and C failing can be calculated with the fault trees and probabilities given below.

  • Design for reliability

    The individual subsystem reliabilities are as follows: Subsystem A = 0.98 Subsystem B = 0.85 Subsystem C = 0.88 Determine the overall system reliability The probabilities of failing are: A = 1 - 0.98 = 0.02 B = 1 - 0.85 = 0.15 C = 1 - 0.88

  • East and west districts

    Given that a student failed the test, what is the posterior probability that the student came from east district?

  • Confidence intervals of employees failing drug tests

    Develop a 99 percent confidence interval for the proportion of applicants that fail the test. Would it be reasonable to conclude that more than 10 percent of the applicants are now failing the test?

  • Calculating Probabilities

    Please see the attached file for a better formatted solution An oil company purchased an option on land in Oklahoma. Preliminary studies assigned the following prior probabilities.

  • Bayes Probability

    For a drug user, the probabilities of these outcomes are 0.65. 0.06, and 0.29. For a nonuser, they are 0.03, 0.72, and 0.25. Use Bayes' rule to find a table of all posterior probabilities. (The prior probability of being a drug user is still 0.05.)

  • Fashion Industries: Applicants Condition of Employment

    Develop a 99 percent confidence interval for the proportion of applicants that fail the test. Would it be reasonable to conclude that more than 10 percent of the applicants are now failing the test?

View More Related Solutions