Answer:
B. A random sample of 2,800 U.S. adults under 35.
Step-by-step explanation:
To have an unbiased and accurate sample, the sample should be representative of the population about which we are inferring.
Also, the bigger the sample size, the less margin of error we will have in the inference.
As the population in this survey is about the US adults under 35, the sample should be selected from this group.
From the options that select from this population, the largest sample is 2,800.
So the answer is Option B.
Answer:
The angles are supplementary.
Step-by-step explanation:
Both angles lie on a straight line. When two angles are right next to each other on a straight line, then they add up to 180...therefore they are supplementary.
Hope this helps!! :D
Answer:
2.5 hours
Step-by-step explanation:
<em>Let t = time in hours for reach friend's house
</em>
<em>(t-1.5) = time for friend to drive her home
</em>
:
Both trips are the same distance, Write a distance equation from this fact:
<em>Distance = speed * time
</em>
<em>Drive distance = Bike distance
</em>
<u>Equation-</u>
<u>step1)</u> 25 (t-1.5) = 10t (here u multiply 25 by t and 25 by 1.5)
<u>step2</u>) 25t - 37.5 = 10t (move 37.5)
<u>step3)</u> 25t - 10t = +37.5 (subtract 25t from 10t)
<u>step4</u>) 15t = 37.5 (divide 37.5 by 15)
<u>step5</u>) t = 2.5 (time it took Luke to reach his aunt's house)
We observe that 20 is 4 more than twice 8. This suggests the time is 1 hour and the rates are
... scooter: 20 mi/h
... bicycle: 8 mi/h
_____
You can let b represent the rate of the bicycle in miles per hour. Then we have (for time in hours and distance in miles) ...
... time = distance/speed
... time = 20/(2b+4) = 8/b
... 20b = 8(2b+4) = 16b +32
... 4b = 32
... b = 8
The rate of the bicycle is 8 mph; that of the scooter is 2*8+4 = 20 mph.
150x4 is 600 volume for the answer
