All Solutions
Page 577: Closure Activity
The probability that a randomly selected show will have an unacceptable sound quality is the following:
$$
p=dfrac{6+10+7}{33+59+40}=0.17
$$
#### (b)
We can notice the following:
$$
dfrac{27}{33}=dfrac{49}{59}=dfrac{33}{40}approx0.82
$$
We can notice that those probabilities are equal, so, there is no association between the sound quality and the microphone used.
The total area is 1400000 minus the rate times the number of years. In 50 years, the area should be “more than” or “greater than” 1200000 square miles:
$$
1400000-x(50)>1200000
$$
or
$$
color{#c34632}1400000-50x>1200000
$$
First, we find the boundary point by replacing the inequality symbol with $=$ then solve for the corresponding equation:
$$
begin{align*}
1400000-50x &=1200000\
-50x &=-200000\
x&=4000
end{align*}
$$
Next, pick a test point except for the boundary point, say $x=0$ to substitute to the inequality:
$$
begin{align*}
1400000-50(0) &> 1200000 \
1400000 &> 1200000 \
end{align*}
$$
The test point is a solution which means all points on this side of the boundary point are part of the solution, which is to the left of it:
$$
color{#c34632}x< 4000
$$
For Lorena, she returned 38 books and has a rate of 16 books per hour so she will book:
$$
38+16t
$$
For Glenda, she returned 52 books and has a rate of 20 books per hour so she will book:
$$
52+20t
$$
Together, they started with a total of 252 books (that must be returned) so we can write the equation:
$$
(38+16t)+( 52+20t)=252
$$
Simplify the left side:
$$
36t+90=252
$$
Subtract 90 from both sides:
$$
36t=162
$$
Divide both sides by 36:
$$
t=4.5
$$
So, they still need $text{textcolor{#c34632}{4.5 hours}}$ more to return all the books.
Lorena’s rate of returning books = 16 books per hour
Glenda’s rate of returning books = 20 books per hour
Hence, Equation for $x$ can be given as:
$$
x(16+20)=252
$$
solving for $x$:
$$
begin{align*}
x(36)&=252\
x&=dfrac{252}{36}\
textcolor{#4257b2}{x}&textcolor{#4257b2}{=7 textrm{ hours }}
end{align*}
$$
The total cost is $$0.75$ times the number of apples, plus $$0.50$ times the number of oranges. Since the money is under $$10$, or less than $$10$:
$$
color{#c34632}0.75a+0.50o<10
$$
0.75a+0.50o<10
$$
The new equation is the following:
$$
g(x)=0.25^x+2
$$
Here we have translation for $2$ units up.
#### (b)
The new equation is the following:
$$
g(x)=0.25^x-3
$$
Here we have translation for $3$ units down.
#### (c)
The new equation is the following:
$$
g(x)=0.25^x+1.3
$$
Here we have translation for $1.3$ units up.
#### (d)
The new equation is the following:
$$
g(x)=0.25^x-18
$$
Here we have translation for $18$ units down.
c) $g(x)=0.25^x+1.3$; d) $g(x)=0.25^x-18$
On the following picture, there is a combination histogram of the given data.
and its spread is $58$, while the center value of Jet Set is $19$
and its spread is $19$.
We can conclude that Jet Set is on tame more often than National Airways.
If Arin wants to summarize his findings, in this case, it is better to use median and $IQR$,
in this situation, it is better because there is a finite number of data.
and see if you have any problems with this chapter.