Purchase Solution

Probabilty and Randomness

Not what you're looking for?

Ask Custom Question

Problem #1
What is the chance of getting eight or fewer tails on 10 flips of a coin?
Problem #2
A salesperson has been losing 25% of potential sales. In a study of 20 random sales contacts from this salesperson, what is the probability of finding 4 or more successful sales?
Problem #3
An automatic transmission repair shop had an established standard to do a certain type of repair. They hired a new mechanic. After six months, they sampled 12 of the new mechanicâ??s repair times versus the standard repair. The new mechanic took more than the standard time on eight of the 12 samples. How confident would the repair shop be in judging that the higher times were due to shop performance rather than to random causes? In your opinion, should the shop keep the new mechanic?
Expectations:
1. Answer questions with clarity and show the detailed steps for calculation.

Purchase this Solution

Solution Summary

Probabilty and Randomness

Solution Preview

1. Prob. of getting 8 or fewer tails = 1 - prob. of getting 9 tails - prob. of getting 10 tails.

Here we use the binomals distribution to find out the probabilities of getting 9 and 10 tails.

P(X = x) = (nCx)(p^x)[(1-p)^(n-x)], where n is total number of trials, x is the number of successes you want, and p is the probability of getting a single success. nCx means n choose x, which is the binomial coefficient. nCx=n!/[x!(n-x)!], where n! = n(n-1)(n-2)...1, 0! = 1 by definition.

So P(X = 9) = (10C9)[(0.5)^9][0.5^1] = 0.0098, and P(X = 10) = ...

Purchase this Solution


Free BrainMass Quizzes
Academic Reading and Writing: Critical Thinking

Importance of Critical Thinking

Production and cost theory

Understanding production and cost phenomena will permit firms to make wise decisions concerning output volume.

Transformational Leadership

This quiz covers the topic of transformational leadership. Specifically, this quiz covers the theories proposed by James MacGregor Burns and Bernard Bass. Students familiar with transformational leadership should easily be able to answer the questions detailed below.

Marketing Research and Forecasting

The following quiz will assess your ability to identify steps in the marketing research process. Understanding this information will provide fundamental knowledge related to marketing research.

Cost Concepts: Analyzing Costs in Managerial Accounting

This quiz gives students the opportunity to assess their knowledge of cost concepts used in managerial accounting such as opportunity costs, marginal costs, relevant costs and the benefits and relationships that derive from them.