/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q8SE Suppose that the events A and B ... [FREE SOLUTION] | 91影视

91影视

Suppose that the events A and B are disjoint and that

each has positive probability. Are A and B independent?

Short Answer

Expert verified

If A and B are disjoint events with positive probabilities are never independent.

Step by step solution

01

Given information

Events A and B are disjoint.

Events A and B has positive probability.

02

Condition for independent events

Two events A and B would be independent if following condition holds true,

\(P\left( {A\;and\;B} \right) = P\left( A \right) \times P\left( B \right)\)

03

Check whether two disjoint events with positive probabilities are independent or not.

The disjoint events never occur at the same time.

If two events A and B are disjoint, then \(P\left( {A\;and\;B} \right) = 0\)

The probability of events A and B being positiveimplies that,

\(\begin{aligned}{l}P\left( A \right) > 0\\P\left( B \right) > 0\end{aligned}\)

It is known that,

\(\begin{aligned}{c}P\left( {A\;{\rm{and}}\;B} \right) = 0\\P\left( A \right) \times P\left( B \right) > 0 \Rightarrow P\left( A \right) \times P\left( B \right) \ne 0\end{aligned}\)

Hence, the two disjoint events A and B with positive probabilities are never independent.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Consider the unfavourable game in Example 2.4.2. This time, suppose that the initial fortune of gambler A is i dollars with i 鈮 98. Suppose that the initial fortune of gambler B is 100 鈭 i dollars. Show that the probability is greater than 1/2 that gambler A losses i dollars before winning 100 鈭 i dollars.

Consider a machine that produces items in sequence. Under normal operating conditions, the items are independent with a probability of 0.01 of being defective. However, it is possible for the machine to develop a 鈥渕emory鈥 in the following sense: After each defective item, and independent of anything that happened earlier, the probability that the next item is defective is\(\frac{{\bf{2}}}{{\bf{5}}}\). After each non-defective item, and independent of anything that happened earlier, the probability that the next item is defective is\(\frac{{\bf{1}}}{{{\bf{165}}}}\).

Please assume that the machine is operating normally for the whole time we observe or has a memory for the whole time we observe. LetBbe the event that the machine is operating normally, and assume that\({\bf{Pr}}\left( {\bf{B}} \right){\bf{ = }}\frac{{\bf{2}}}{{\bf{3}}}\). Let\({{\bf{D}}_{\bf{i}}}\)be the event that theith item inspected is defective. Assume that\({{\bf{D}}_{\bf{1}}}\)is independent ofB.

a. Prove that\({\bf{Pr}}\left( {{{\bf{D}}_{\bf{i}}}} \right){\bf{ = 0}}{\bf{.01}}\) for alli. Hint:Use induction.

b. Assume that we observe the first six items and the event that occurs is\({\bf{E = D}}_{\bf{1}}^{\bf{c}} \cap {\bf{D}}_{\bf{2}}^{\bf{c}} \cap {{\bf{D}}_3} \cap {{\bf{D}}_4} \cap {\bf{D}}_{\bf{5}}^{\bf{c}} \cap {\bf{D}}_{\bf{6}}^{\bf{c}}\). The third and fourth items are defective, but the other four are not. Compute\({\bf{Pr}}\left( {{\bf{B}}\left| {\bf{E}} \right.} \right)\).

For any two events A and B with Pr(B) > 0, prove that Pr(Ac|B) = 1 鈭 Pr(A|B).

Suppose that in Example 2.3.4 in this section, the item selected at random from the entire lot is found to be non-defective. Determine the posterior probability that it was produced by machine\({{\bf{M}}_{\bf{2}}}\).

Suppose that a balanced die is rolled three times, and let\({X_i}\)denote the number that appears on the ith roll (i = 1, 2, 3). Evaluate\({\rm P}\left( {{X_1} > {X_2} > X3} \right)\).

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.