Answer: Mean = 20 and standard deviation = 4
Step-by-step explanation:
Let x represents the success of getting the correct answer.
Here, the total number of trials(n) = 100
The probability of getting the correct answer, p = 1/5
Thus, the mean of the number of correct answer,
Now, the standard deviation,
Thus, First option is correct.
Using the binomial distribution, the probabilities are given as follows:
a) 0.4159 = 41.59%.
b) 0.5610 = 56.10%.
c) 0.8549 = 85.49%.
<h3>What is the binomial distribution formula?</h3>The formula is:
The parameters are:
For this problem, the values of the parameters are:
n = 3, p = 0.76.
Item a:
The probability is P(X = 2), hence:
Item b:
The probability is P(X < 3), hence:
P(X < 3) = 1 - P(X = 3)
In which:
Then:
P(X < 3) = 1 - P(X = 3) = 1 - 0.4390 = 0.5610 = 56.10%.
Item c:
The probability is:
More can be learned about the binomial distribution at brainly.com/question/24863377
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Answer:
B. 60°
Step-by-step explanation:
1. The measure of all angles in a triangle sum up to 180°. This means that y + y + 60 = 120.
2. (Solving)
Step 1: Simplify both sides of the equation.
Step 2: Subtract 60 from both sides.
Step 3: Divide both sides by 2.
Step 4: Check if solution is correct.
Therefore, the answer is B. 60°.