Answer:
A.
Step-by-step explanation:
If we assume that the population of the town is proportional to the random people selected to take the survey, then we can say that the answer is A, People at least 50 years old are the largest age group in town. Since the survey is random and the percentage of the 50-year old population group is higher when individually compared to the other groups, we can assume that the town's population consists of a high number of people who are 50-years old or older.
And although it is not a given answer choice, it would actually make more sense to say that out of the number of people that took the survey, those who were 50 years old or older consisted of the largest age group.

A reflection about the x axis, about y=0, is the mapping (x',y')=(x,-y) so

A dilation of 2 is the mapping (x'',y'')=(2x', 2y')
So




We can rewrite that without the primes and combine the powers of 2.

Let's graph these and see if we're close,
Plot y= (1/4)^x, y= - (1/4)^{x}, y = - 2^{1-x}
Answer:
(a)
The probability that you stop at the fifth flip would be

(b)
The expected numbers of flips needed would be

Therefore, suppose that
, then the expected number of flips needed would be 1/0.5 = 2.
Step-by-step explanation:
(a)
Case 1
Imagine that you throw your coin and you get only heads, then you would stop when you get the first tail. So the probability that you stop at the fifth flip would be

Case 2
Imagine that you throw your coin and you get only tails, then you would stop when you get the first head. So the probability that you stop at the fifth flip would be

Therefore the probability that you stop at the fifth flip would be

(b)
The expected numbers of flips needed would be

Therefore, suppose that
, then the expected number of flips needed would be 1/0.5 = 2.
Answer:
The percentage of students who scored below 620 is 93.32%.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:

Percentage of students who scored below 620:
This is the pvalue of Z when X = 620. So



has a pvalue of 0.9332
The percentage of students who scored below 620 is 93.32%.
Answer:

Step-by-step explanation:
We have been given that at midnight, the temperature was
. At noon, the temperature was
.
Since our temperature has increased to 23 degree Fahrenheit from -8 degree Fahrenheit, we can represent this increase in temperature as:

Therefore, the expression
represents the increase in temperature.