Answer:
b. Invalid, because the sample may not be representative of the population.
Step-by-step explanation:
A sample of around 10% of the population is needed to be representative.
In this question:
We have a population of 500,000, and a sample of 10,000.
10,000/500,000 = 1/50 = 0.02 = 2% of the population, so not representative, and option b is correct.
Answer:
a)0.08 , b)0.4 , C) i)0.84 , ii)0.56
Step-by-step explanation:
Given data
P(A) = professor arrives on time
P(A) = 0.8
P(B) = Student aarive on time
P(B) = 0.6
According to the question A & B are Independent
P(A∩B) = P(A) . P(B)
Therefore
& 
is also independent
= 1-0.8 = 0.2
= 1-0.6 = 0.4
part a)
Probability of both student and the professor are late
P(A'∩B') = P(A') . P(B') (only for independent cases)
= 0.2 x 0.4
= 0.08
Part b)
The probability that the student is late given that the professor is on time
= 
= 
= 0.4
Part c)
Assume the events are not independent
Given Data
P
= 0.4
=
= 0.4
= 0.4 x P
= 0.4 x 0.4 = 0.16
= 0.16
i)
The probability that at least one of them is on time
= 1-
= 1 - 0.16 = 0.84
ii)The probability that they are both on time
P
= 1 - 
= 1 - ![[P({A}')+P({B}') - P({A}'\cap {B}')]](https://tex.z-dn.net/?f=%5BP%28%7BA%7D%27%29%2BP%28%7BB%7D%27%29%20-%20P%28%7BA%7D%27%5Ccap%20%7BB%7D%27%29%5D)
= 1 - [0.2+0.4-0.16] = 1-0.44 = 0.56
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Define adult and student tickets
------------------------------------------
Let the number of adult tickets be x
Adult tickets = x
Student tickets = x + 69
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Form equation and solve for x
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x + x + 69 = 569
2x + 69 = 569 ← Combine like terms
2x = 569 - 69 ← Subtract 69 from both sides
2x = 500
x = 250 ← Divide by 2 to find x
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Find the number of adult tickets and student tickets
------------------------------------------------------------------------------------
Adult tickets = x = 250
Student tickets = x + 69 = 319
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Answer: Adult tickets = 250 ; Student tickets = 319
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Yes. 3/2 is equivalent to 1.5
The answer would be 9.9
Pemdas
9.7-2.4= 7.3
2.6+7.3 = 9.9
