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:
We want to determine a 95% confidence interval for the mean total cholesterol level of all males.
Number of sample, n = 355
Mean, u = 185 mg
Standard deviation, s = 16
For a confidence level of 95%, the corresponding z value is 1.96. This is determined from the normal distribution table.
We will apply the formula
Confidence interval
= mean +/- z ×standard deviation/√n
It becomes
185 +/- 1.96 × 16/√355
= 185 +/- 1.96 × 0.849
= 185 +/- 1.66404
The lower end of the confidence interval is 185 - 1.66404 =183.336
The upper end of the confidence interval is 185 + 1.66404 = 186.66
Therefore, with 95% confidence interval, the mean total cholesterol level of all males is between 183.336 mg and 186.66 mg
Answer:
10oz
Step-by-step explanation:
Solve
<h2>

</h2><h2>
x=10</h2><h2>
</h2>
IK its an obtuse angleeee if that helps
Answer:
162
Step-by-step explanation:
260/2=130
130+32=162