Using conversion of units and volume of a cylinder, it is found that 23.17 cubic yards of concrete are needed, option D.
The volume of a cylinder of radius r and height h is given by:

In this problem:
- We want the volume in cubic yards, thus, the units of radius and height have to be in yards.
- 32 inches in diameter, thus 16 inches of radius. Since each inch has 0.0278 yards, this is a radius of 0.44 yards, thus
. - Height of 8 feet, and since each feet has 0.33 yards, this is a height of 2.67 yards, thus

- 14 poles, thus the volume is multiplied by 14.
Then:

23.17 cubic yards of concrete are needed, option D.
A similar problem is given at brainly.com/question/22789697
The problem above uses the concept of ratio and proportion. The ratio between the cost and amount of the organic milk should always be equal. The proportion between two cases is shown below,
($2.52 / 0.5 gallon) = (x / 4 gallons)
Solving for x gives x = 20.16. Therefore, 4 gallons of organic milk costs $20.16.
Answer:
B. The observational study is a cross-sectional study because information is collected at a specific point in time.
Step-by-step explanation:
1) There are three types of Observational Studies: Case-control, cross-sectional and Cohort.
2) Since the researchers collected information from those 1800 adults at a certain time, then we can call it a cross-sectional study. It does not provide solid results since the research was not done over a period to collect further information. We don't know, for example, much more than what that association deeply mean.
3) If we wonder more, then the researchers would have to track those adults over a given period, i.e. a Cohort would be necessary.
4) Moreover, it's not "retrospective" for virtually every question, always makes us look back somehow, and it does not categorize a kind of observational study.
A) domain: [ -5 5 ] range: [ -10 -2 ]
b) y intercept: -2 x intercept: -2 2
c) y= -2
d) x= -2 x= 2
e) None