Answer:
5.96% probability that exactly 3 people in the sample are afraid of being alone at night.
Step-by-step explanation:
For each person, there are only two possible outcomes. Either they are afraid of being alone at night, or they are not. The probability of a person being afraid of being alone at night is independent of any other person. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
In which 
is the number of different combinations of x objects from a set of n elements, given by the following formula.
And p is the probability of X happening.
5% of Americans are afraid of being alone in a house at night.
This means that 
If a random sample of 20 Americans is selected, what is the probability that exactly 3 people in the sample are afraid of being alone at night.
This is P(X = 3) when n = 20. So
5.96% probability that exactly 3 people in the sample are afraid of being alone at night.
Answer:
Step-by-step explanation:
Firstly, note that -2i really is just z = 0 + (-2)i, so we see that Re(z) = 0 and Im(z) = -2.
When we're going from Cartesian to polar coordinates, we need to be aware of a few things! With Cartesian coordinates, we are dealing explicitly with x = blah and y = blah. With polar coordinates, we are looking at the same plane but with angle and magnitude in consideration.
Graphing z = -2i on the Argand diagram will look like a segment of the y axis. So we ask ourselves "What angle does this make with the positive x axis? One answer you could ask yourself is -90°! But at the same time, it's 270°! Why do you think this is the case?
What about the magnitude? How far is "-2i" stretched from the typical "i". And the answer is -2! Well... really it gets stretched by a factor of 2 but in the negative direction!
Putting all of this together gives us:
z = |mag|*(cos(angle) + isin(angle))
= 2*cos(270°) + isin(270°)).
To verify, let's consider what cos(270°) and sin(270°) are.
If you graph cos(x) and look at 270°, you get 0.
If you graph sin(x) and look at 270°, you get -1.
So 2*(cos(270°) + isin(270°)) = 2(0 + -1*i) = -2i as expected.
1000 candy bars ... $350
1 candy bar ... $x = ?
If you would like to know what is the unit cost per candy bar, you can calculate this using the following steps:
1000 * x = 350 * 1
1000 * x = 350 /1000
x = 350 / 1000
x = $0.35
Result: She can buy 1 candy bar for $0.35, so the correct result would be B) $.35.
Answer:
Step-by-step explanation:
The figure B is the scaled copy of the figure A.
The both figures are similar to each other.
<u>The scale factor is the ratio of corresponding sides of figure B to A:</u>
or
