The total number of fish bought was 320. And you know she bought two types of fish. The best way to solve this is guess and check. It would be the fastest. So she bought 7 times as many trigger-fish as parrot fish that means the number of trigger-fish bought was 7p. This means 320 = 7p +p. So all you do is take educated guesses for the number of parrot fish and check if it is right. So if she bought 50 parrot fish. 7(50) + 50 = 400. Close but a bit high. Lets keep guessing. 7(35) + 35 = 245. So now we know the answer is between 50 and 35. So lets try 40. 7(40) + 40 =320. That works so we know she bought 40 parrot fish and 280 trigger-fish.
we have
Min=26
Q1=67
Q2=80
Q3=87
Max=100
Mean=76
Mode=100
standard deviation=76
IQR=20
so
In this problem
the mean is equal to the standard deviation
therefore
<h2>The standard deviation is incorrectly</h2>
Answer:
0.173 probability that she gets exactly three questions correct.
Step-by-step explanation:
For each question, there are only two possible outcomes. Either she guesses the correct answer, or she does not. The probability of guessing the correct answer for a question is independent of other questions. 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.
Seven questions:
This means that 
Each question has four choices.
Abby guesses, which means that 
Find the probability to the nearest thousandth, that Abby gets exactly three questions correct.
This is P(X = 3).


70 miles per hour
5280 feet per mile
5280 x 70 = 369600 feet per hour
3600 seconds per hour
369600 divided by 3600 =
102.67 feet per second (rounded to the nearest hundredth)
Multiply both sides of the equation by 12. Move the variables to the left-hand side and change its sign. Move the constant to the left-hand side and change its sign. Collect like terms. Add the numbers. Divide both sides of the equation by 12.
1/2 x - 5= - 1/2 x + 19/4
6x -20= - 6x + 57
6x + 6x= 57 + 20
12x= 57 + 20
12x= 77
ANSWER
x = 77/12
Alternative Form .
x = 6 5/12, x= 6.416