Answer:
22 2/9
Step-by-step explanation:
When z "varies jointly" with x and y, it can be described by the formula
z = kxy
Here, we have bags of mulch (n) varying jointly with area (a) and depth (d), both in feet. The given information can let us find the value of k.
n = kad
10 = k·(120)(1/4)
10/30 = k = 1/3 . . . . . divide by the coefficient of k
Now, we can fill in the other values of interest.
n = (1/3)·(200)·(1/3) = 200/9
n = 22 2/9
You need 22 2/9 bags of mulch to cover 200 ft² to a depth of 4 inches.
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<em>Comment on the problem</em>
This problem requires the formula be written with both area and depth expressed in feet, yet it gives depth in inches. The formula can also be written using depth in inches. In that case, k = 1/36.
Answer:
C
Step-by-step explanation:
C, because the second line keeps adding 6 to it and, the third line keeps adding 7.
Understanding the Question
This may not be the actual way that the US government prepares the CPI, but it will provide a comparison.
You can set up a proportion. The base number for the CPI is 38.8 in 1970. That number (38.8) has more than doubled to get to 82.4, which also tells us that there was inflation. What your parents and grandparents bought in 1970 went to double the amount in 1980. Gasoline certainly did that.
Givens
CPI in 1970 = 38.8
CPI in 1980 = 82.4
Eggs 1970 = 0.25
Edgs 1980 = X
Formula substitution and solution
CPI 1970 / CPI 1980 = cost of eggs 1970 / cost of eggs 1980
38.8/82.4 = 0.25 / x Cross multiply
38.8 * x = 0.25 * 82.4
38.8 * x = 20.625
x = 20.628 /38.8
x = 0.53 dollars of 53 cents.
53 cents in 1980 which is slightly double as predicted.
Footnote
As a matter of interest, my wife tells me that eggs now cost about 3.58 where we live. That's almost 7 times as expensive as they were in 1980. Something to think about. By the way, the price quoted is in Canada.
Answer:
The radius of convergence is half of the length of the interval of convergence. If the radius of convergence is R then the interval of convergence will include the open interval: (a − R, a + R). To find the radius of convergence, R, you use the Ratio Test.
