The answer to the question is 3 8/33
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:
a.
500x+0.04=y
400x+0.05=y
for percentages move decimal to the left twice
All will apply except for (A, C, and E) because those lengths are less than 4/6. So (B, D and F) are the correct answers.
Answer:
B
Step-by-step explanation:
think of the ratios as equivalent fractions. 2 over 14 is NOT equal to 3 over 42.