Answer:
(a) The expected number of guests until the next one pays by American Express credit card is 4.
(b) The probability that the first guest to use an American Express is within the first 10 to checkout is 0.0215.
Step-by-step explanation:
The random variable <em>X</em> can be defined as the number of guests until the next one pays by American Express credit card
The probability that a guest paying by American Express credit card is, <em>p</em> = 0.20.
The random variable <em>X</em> follows a Geometric distribution since it is defined as the number of trials before the first success.
The probability mass function of <em>X</em> is:

(a)
The expected value of a Geometric distribution is:

Compute the expected number of guests until the next one pays by American Express credit card as follows:



Thus, the expected number of guests until the next one pays by American Express credit card is 4.
(b)
Compute the probability that the first guest to use an American Express is within the first 10 to checkout as follows:


Thus, the probability that the first guest to use an American Express is within the first 10 to checkout is 0.0215.
Answer:
49°
Step-by-step explanation:
The given information that BC=DC tells you triangle BCD is an isosceles triangle and that angle y is one of the two equal base angles. Then ...
y + y + 82 = 180 . . . . . the sum of angle measures is 180 degrees
2y = 98 . . . . subtract 82
y = 49 . . . . . divide by 2
The measure of y is 49°.
Okay what you need I’ll help you with whatever
Answer:
San Francisco
Step-by-step explanation:
Geneva is -3 °C. Nikki's hometown will be 12° warmer, or +9 °C. The city in the table with that temperature is San Franscisco.