Westonci.ca is your trusted source for finding answers to all your questions. Ask, explore, and learn with our expert community. Our platform connects you with professionals ready to provide precise answers to all your questions in various areas of expertise. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

a. What is the probability that this couple spends 45 dollars or more?

b. Suppose that the restaurant is currently running a promotion with a 10% discount if the total amount spent by a table is 45 dollars or more. What is expected total amount the couple actually has to pay?


A What Is The Probability That This Couple Spends 45 Dollars Or More B Suppose That The Restaurant Is Currently Running A Promotion With A 10 Discount If The To class=

Sagot :

Using the probability table, it is found that:

  • a) There is a 0.25 = 25% probability that this couple spends 45 dollars or more.  
  • b) The expected amount the couple actually has to pay is $36.85.

Item a:

To find the probabilities involving the total cost, we have to add the variables X and Y from the table, then:

[tex]P(X = 30) = P(X = 15|Y = 15) = 0.2[/tex]

[tex]P(X = 35) = P(X = 15|Y = 20) + P(X = 20|Y = 15) = 0.15 + 0.15 = 0.3[/tex]

[tex]P(X = 40) = P(X = 15|Y = 25) + P(X = 20|Y = 20) + P(X = 25|Y = 15) = 0.05 + 0.15 + 0.05 = 0.25[/tex]

[tex]P(X = 45) = P(X = 20|Y = 25) + P(X = 25|Y = 20) = 0.1 + 0.1 = 0.2[/tex]

[tex]P(X = 50) = P(X = 25|Y = 25) = 0.05[/tex]

The probability involving values of 45 or more is:

[tex]P(X \geq 45) = P(X = 45) + P(X = 50) = 0.2 + 0.05 = 0.25[/tex]

0.25 = 25% probability that this couple spends 45 dollars or more.

Item b:

For a discrete distribution, the expected value is the sum of each outcome multiplied by it's respective probability, hence, involving the 10% discount for prices above $45:

[tex]E(X) = 0.2(30) + 0.3(35) + 0.25(40) + 0.9[0.2(45) + 0.05(50)] = 36.85[/tex]

The expected amount the couple actually has to pay is $36.85

A similar problem is given at https://brainly.com/question/25782059