Answer:
c^3 + c^2 - 7c + 20
Step-by-step explanation:
First, expand the expression using distributive property.
c^2(c+4) - 3c(c+4) + 5(c+4)
c^3 + 4c^2 - 3c^2 - 12c + 5c + 20
Lastly, simplify like terms.
c^3 + c^2 - 7c + 20
Divide the amount of teenagers that smoked by the total population:
Multiply this decimal by 100 to convert into a percentage:
To round to the nearest decimal place, look at the hundredths value:
8.5
3
3 > 5
8.53 -> 8.5
8.5% of teenagers reported that they smoked at least one cigarette.
The best design for this experiment would be a repeated measures design. This is ideal to determine if eating an apple makes you healthy.
<h3>What is an experimental design?</h3>
An experimental design refers to the general structure of an experiment including how people are distributed into the control and experimental group to test a specific phenomenon.
<h3>What is a repeated measures design?</h3>
In a repeated measures design all participants are both parts of the control group, in this case, people who do not eat apples, and the experimental group, or people who eat apples.
<h3>What does this design imply?</h3>
In the case of determining if eating an apple every day, this design implies:
- All participants will be asked to not eat apples every day for a specific period such as one or two months, and health levels will be measured during this time.
- After the first step, all participants will be asked to eat an apple every day during the period, and their health will be measured.
- The researcher can compare the results of each participant, which is more accurate than comparing one participant to another.
Learn more about experiments in: brainly.com/question/1452319
Answer:
A
Step-by-step explanation:
Answer:
x = 39.1
Step-by-step explanation:
To find the mean, add up all the data points and then divide by the number of data points
(31.7+ 42.8+ 26.4+ x)/4 = 35
Multiply each side by 4
(31.7+ 42.8+ 26.4+ x)/4*4 = 35*4
(31.7+ 42.8+ 26.4+ x) = 140
Combine like terms
100.9+x = 140
Subtract 100.9 from each side
x = 140-100.9
x = 39.1
