Answer:
58%
Step-by-step explanation:
This is a problem of conditional probability.
Let A represent the event that student has dark hair.
So P(A) = 55% = 0.55
Let B represents the event that student has blue eyes.
So, P(B) = 60% = 0.60
Probability that student has blue eyes and dark hairs = P(A and B) = 35% = 0.35
We are to find the probability that a randomly selected student will have dark hair, given that the student has blue eyes. Using the given formula and values, we get:

Therefore, there is 0.58 or 58% probability that the student will have dark hairs, given that the student has blue eyes.
Answer:
23 cards.
Step-by-step explanation:
After Monday, Esteban has 12 cards.
After Tuesday, Esteban has 12 + 24 = 36 cards.
He gave to his sister x cards.
36 - x = 13
36 = 13 + x
23 = x
Answer:
A sample of 16577 is required.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the z-score that has a p-value of
.
The margin of error is of:

99% confidence level
So
, z is the value of Z that has a p-value of
, so
.
She wants to estimate the proportion using a 99% confidence interval with a margin of error of at most 0.01. How large a sample size would be required?
We have no estimation for the proportion, and thus we use
, which is when the largest sample size will be needed.
The sample size is n for which M = 0.01. So






Rounding up:
A sample of 16577 is required.
Answer:
1
a. 5
b. 32
c. 130
d. 26
2
a. 5.65234
b. 5652.34
c. 8.1253758
d. 8125375.8
Step-by-step explanation: