In a recent survey, 80% of the community favored building a police substation in their neighborhood. If 15 citizens are chosen,
1 answer:
Answer:
The mean number favoring the substation is 12 citizens.
Step-by-step explanation:
For each citizen surveyed, there are only two possible outcomes. EIther they favored building a police substation in their neighborhood, or they opposed. This means that we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, with p probability, and X can only have two outcomes.
Has an expected value of:
In this problem, we have that:
E(X) = 15*0.8 = 12.
The mean number favoring the substation is 12 citizens.
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Let
<span>A------> (−3, −11)
B------> (6, 4)
step 1
find the slope m point A and point B
m=(y2-y1)/(x2-x1)-----> </span>m=(4+11)/(6+3)----> m=15/9---> 5/3
step 2
with m=5/3 and point B (6, 4) find the equation of a line
y-y1=m*(x-x1)-----> y-4=(5/3)*(x-6)---> y=(5/3)x-6
case <span>a. they have the same slope------> is not correct
because
</span><span>y=35x−6------> the slope m=35
</span>y=(5/3)x-6---> the slope m =5/3
case <span>b. they have the same x-intercept.----> is not correct
because
</span>the x-intercept is for y=0
y=35x−6-----> 0=35x-6----> 35x=6-----> x=6/35
the x-intercept is the point (6/35,0)
y=(5/3)x-6----> 0=(5/3)x-6----> (5/3)x=6---> x=18/5
the x-intercept is the point (18/5,0)
case <span>c. the two lines are perpendicular. do. they have the same y-intercept-----> is nor correct
because
if two lines are perpendicular
m1*m2=-1-------> </span><span>this condition is not satisfied
</span>
the y intercept is for x=0
y=35x−6-------> y=-6
the y intercept is the point (0,-6)
y=(5/3)x-6-----> y=-6
the y intercept is the point (0,-6)
they have the same y-intercept but the two lines are not perpendicular
see the attached figure
<span>A------> (−3, −11)
B------> (6, 4)
step 1
find the slope m point A and point B
m=(y2-y1)/(x2-x1)-----> </span>m=(4+11)/(6+3)----> m=15/9---> 5/3
step 2
with m=5/3 and point B (6, 4) find the equation of a line
y-y1=m*(x-x1)-----> y-4=(5/3)*(x-6)---> y=(5/3)x-6
case <span>a. they have the same slope------> is not correct
because
</span><span>y=35x−6------> the slope m=35
</span>y=(5/3)x-6---> the slope m =5/3
case <span>b. they have the same x-intercept.----> is not correct
because
</span>the x-intercept is for y=0
y=35x−6-----> 0=35x-6----> 35x=6-----> x=6/35
the x-intercept is the point (6/35,0)
y=(5/3)x-6----> 0=(5/3)x-6----> (5/3)x=6---> x=18/5
the x-intercept is the point (18/5,0)
case <span>c. the two lines are perpendicular. do. they have the same y-intercept-----> is nor correct
because
if two lines are perpendicular
m1*m2=-1-------> </span><span>this condition is not satisfied
</span>
the y intercept is for x=0
y=35x−6-------> y=-6
the y intercept is the point (0,-6)
y=(5/3)x-6-----> y=-6
the y intercept is the point (0,-6)
they have the same y-intercept but the two lines are not perpendicular
see the attached figure