The y- intercept has to be a point in the line where x is 0. Which means that in this case it would be -4.
To find the slope, use the formula: rise over run —> y2 - y1/x2 - x1
Choose any two coordinates and plug them in. Then simplify. Let me know if you have any questions by commenting:)
Hope I helped:)
Answer:
x = -9
Step-by-step explanation:
You are solving for x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
First, subtract 7 from both sides:
2x + 7 (-7) = -11 (-7)
2x = -11 - 7
2x = -18
Next, divide 2 from both sides:
(2x)/2 = (-18)/2
x = -18/2
x = -9
x = -9 is your answer.
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Answer:
See below.
Step-by-step explanation:
The graph is very unclear, but if you look at x = 2, and you go up until you intersect a point on the line, the y-coordinate of that point is the value written on the graph to the left of the y-axis.
Answer:
a) E(X) = 71
b) V(X) = 20.59
Sigma = 4.538
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>According to a 2010 study conducted by the Toronto-based social media analytics firm Sysomos, 71% of all tweets get no reaction. That is, these are tweets that are not replied to or retweeted (Sysomos website, January 5, 2015).
</em>
<em>
Suppose we randomly select 100 tweets.
</em>
<em>a) What is the expected number of these tweets with no reaction?
</em>
<em>b) What are the variance and standard deviation for the number of these tweets with no reaction?</em>
This can be modeled with the binomial distribution, with sample size n=100 and p=0.71, as the probability of no reaction for each individual tweet.
The expected number of these tweets with no reaction can be calcualted as the mean of the binomial random variable with these parameters:

The variance for the number of these tweets with no reaction can be calculated as the variance of the binomial distribution:

Then, the standard deviation becomes:
