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:
- <u>Quantitative.</u>
- <u>Discrete.</u>
- <u>Interval Scale.</u>
Step-by-step explanation:
- The IQ scores are measured numerically. This makes it quantitative data. Quantitative data provide numerical measures which can be used to perform arithmetric operations such as addition, subtraction, multiplication and division. Results from these kind of data can be used to provide meaningful and explanatory results to certain phenomena.
- IQ scores are discrete because they are always expressed as integers. that is in whole numbers and not in fractions e.g 100, 120, 60.
- The level of measurement is on an interval scale because the difference between values have meanings. Larger values mean higher IQ. for example, the difference in IQ numbers between two people for represents something real.
X is 7 more than y
x>y then
difference betwen squares is 161 so
x=7+y
and
x²-y²=161
so
x=7+y
sub that for x in other equation
(7+y)²-y²=161
y²+14y+49-y²=161
14y+49=161
minus 49 both sides
14y=112
divide both sides by 14
y=8
sub back
x=7+y
x=7+8
x=15
the numbers are 15 and 8
8.5x-6.1=-7.1
40x-6.1=-7.1
40x=-7.1+6.1
40x=-1
solution= x= -0.025
Answer:
Step-by-step explayesnation:
yes
