Answer:
The value of E [Z] is 0.50.
Step-by-step explanation:
The expected value is computed using the formula:

Denote the three dices as follows:
X₁ = a four-sided die
X₂ = a six-sided die
X₃ = a 12-sided die
Define the indicator variables as follows:

The probability of rolling a 4 in the three dices are as follows:

Compute the value of E [Z] as follows:


Thus, the value of E [Z] is 0.50.
There is only one statement that is true: B. The graph of the function is a parabola.
<h3>How to study and interpret the characteristics of quadratic equations</h3>
In this question we have a <em>quadratic</em> equation, whose characteristics have to be inferred and analyzed. We need to prove each of the five choices presented in the statement:
Choice A:
If we know that x = - 10, then we evaluated it at the function:
f(- 10) = (- 10)² - 5 · (- 10) + 12
f(- 10) = 162
False
Choice B:
By analytical geometry we know that all functions of the form y = a · x² + b · x + c always represent parabolae.
True
Choice C:
The <em>quadratic</em> function opens up as its <em>leading</em> coefficient is greater that 0.
False
Choice D:
If we know that x = 20, then we evaluate it at the function:
f(20) = 20² - 5 · (20) + 12
f(20) = 312
False
Choice E:
If we know that x = 0, then we evaluate it at the function:
f(0) = 0² - 5 · (0) + 12
f(0) = 12
There is only one statement that is true: B. The graph of the function is a parabola.
To learn more on quadratic equations: brainly.com/question/1863222
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Answer:

Step-by-step explanation:


The number of ants in his farm after 12 weeks is 218.
Step-by-step explanation:
Step 1:
It is given that there are 15 ants initially and the ant population increases by 25% each week.
This is an exponential rate of increase that can be modeled by the following equation:
Number of ants after n weeks = Initial number of ants * 
Step 2:
Rate of increase = 25% = 25 / 100 = 0.25
Number of weeks = 12
Number of ants after 12 weeks = 15*
= 218.27 (rounded off to 218)
Step 3:
Answer:
The number of ants in his farm after 12 weeks is 218.