Answer:
(a) The mean or expected value of <em>X </em>is 2.2.
(b) The standard deviation of <em>X</em> is 1.3.
Step-by-step explanation:
Let <em>X</em> = number of times the traffic light is red when a commuter passes through the traffic lights.
The probability distribution of <em>X</em> id provided.
The formula to compute the mean or expected value of <em>X </em>is:

The formula to compute the standard deviation of <em>X </em>is:

The formula of E (X²) is:

(a)
Compute the expected value of <em>X</em> as follows:

Thus, the mean or expected value of <em>X </em>is 2.2.
(b)
Compute the value of E (X²) as follows:

Compute the standard deviation of <em>X</em> as follows:

Thus, the standard deviation of <em>X</em> is 1.3.
Answer: B.
Step-by-step explanation: Mr. Bates made the pretzel 35% SMALLER. That means that the remains of the pretzel is 65% of the original 100% of the pretzel. Therefore, the answer is B.
Answer:
total sample space is 91
no of cookies in dog shape is 30
therefore
p(d)=30/91
Answer:
At the start of 2014, the population was growing at 8.34 million people per year.
At the start of 2015, the population was growing at 8.39 million people per year.
Step-by-step explanation:
To find how fast was the population growing at the start of 2014 and at the start of 2015 we need to take the derivative of the function with respect to t.
The derivative shows by how much the function (the population, in this case) is changing when the variable you're deriving with respect to (time) increases one unit (one year).
We know that the population, P(t), of China, in billions, can be approximated by 
To find the derivative you need to:

To find the population growing at the start of 2014 we say t = 0

To find the population growing at the start of 2015 we say t = 1

To convert billion to million you multiple by 1000

Hi there!
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I believe your answer is:
(-3, -1) and (1, 3)
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Here’s why:
- I have graphed the two equations given on a graphing program.
- When graphed, they pass at points (-3, -1) and (1,3). Therefore, they are the solutions to the system.
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See the graph attached.
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Hope this helps you. I apologize if it’s incorrect.