The answer is 5 divided by 1/3
Write the equation of the lines in slope-intercept form (y=mx+b)
First equation: It is already in slope-intercept form

Second equation: solve y:

Identify the slope of each line:
If two or more lines have the same slope then the lines are parallel
If two lines have slopes that are negative reciprocals then the lines are perpendicular
The two given lines have the same slope: 2/5. Then, they are parallel lines
48-X or C-48 would be the answer
Whisper-20dB
Quiet Residence-30dB
Soft stereo in Residence-40dB
Average Speech-60dB
Cafeteria-80dB
Pneumatic Jackhammer-90dB
Loud crowd noise-100dB
Accelerating Bike-100dB
Rock concert-120dB
Jet Engine (75 ft away)-140dB
(1)Mode=100dB (since 100 is occurring the maximum no. of times, i.e. it has the highest frequency of 2)
(2)Mean=sum of observations/Total number of observations
=(20+30+40+60+80+90+100+100+120+140)/10
=770/10=10dB
(3)Median= 1/2[{n/2}th observation + {(n/2)+1}th observation], where, n=total no. of observations
So, 1/2[{10/2}th observation + {(10/2)+1}th observation]
=1/2[5th observation+6th observation]
=1/2[80+90] [Because:5th observation=80dB and 6th=90dB]
=1/2(170)
=85
Therefore, median=85dB
1 quart = 32 ounces
2 x 32 = 64
$6.40 divided by 64 ounces
.10 per ounce