Answer:
Margin of error of 0.0485 hours.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
That is z with a pvalue of 
, so Z = 1.96.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
In this question:
The margin of error is of:
Margin of error of 0.0485 hours.
I think the answer is B.
But my second choice would be C.
Answer:
Option D y=3
Step-by-step explanation:
The question in English is
Which of the following functions is a constant function?
we know that
A <u>constant function</u> is a function whose output value is the same for every input value
so
<u><em>Verify each case</em></u>
case A) y=x+1
This is not a constant function, this is a linear equation
Is a function whose output value is different for every input value
case B) y=x+2
This is not a constant function, this is a linear equation
Is a function whose output value is different for every input value
case C) x=y+3
This is not a constant function, this is a linear equation
Is a function whose output value is different for every input value
case D) y=3
This is a constant function
Is a function whose output value is the same for every input value
Assuming that the probability of boys and girls is equal (in reality slightly more boys than girls are born), the probability is 1/2, simply because the older girl's gender is given and therefore not a part of the probability.
This question comes from the 'boy or girl paradox', a.k.a. the Mrs Smith Problem.
X + y = 5
xy = 12
x + y = 5
y = -x + 5
xy = 12
x(-x + 5) = 12
x(-x) + x(5) = 12
-x² + 5x = 12
- 12 - 12
-x² + 5x - 12 = 0
x² - 5x + 12 = 0
x = 5 ± √25 - 48
2
x = -5 ± √-23
2
x = -5 ± 4.79i
2
x = -5 + 4.79i or x = -5 - 4.79i
2 2
x = -2.5 + 2.395i or x = -2.5 - 2.395i
y = -2.5 - 2.395i or y = -2.5 + 2.395i
The two numbers that add up to 5 and multiply to 12 is -2.5 ± 2.395i, which is -2.5 + 2.395i and -2.5 - 2.395i.
