Let C be the amount of compost
T be the amount of topsoil
Each compost cost = $25
Cost of C compost = 25C
Each topsoil cost = $15
Cost of T topsoil = 15T
Amount of compost + amount of topsoil = 10
C + T = 10 -------> Equation 1
cost of C compost + cost of T topsoil = 180
25C + 15T = 180 --------> equation 2
Solve the first equation for C
C + T = 10
C = 10 - T
Now plug it in second equation
25C + 15T = 180
25 ( 10 - T) +15T = 180
250 - 25T + 15T = 180 (combine like terms)
250 - 10 T = 180 (Subtract 250 on both sides)
-10T = 180 - 250
-10T = -70 ( divide by -10 on both sides)
T = 7
She purchased 7 cubic yards of topsoil .
Answer:
The range of values likely to contain the true value of the population parameter is between 44% and 52%.
Step-by-step explanation:
Confidence interval concepts:
A confidence interval has two bounds, a lower bound and an upper bound.
These bounds are dependent of the sample mean and of the margin of error.
The lower bound is the sample mean subtracted by the margin of error, while the upper bound is the margin of error added to the sample mean.
The confidence interval is likely to contain the true value of the population parameter.
In this question:
Sample mean: 48%
Margin of error: 4%
48 - 4 = 44%
48 + 4 = 52%
The range of values likely to contain the true value of the population parameter is between 44% and 52%.
Answer:
18.84
Step-by-step explanation:
The formula for circumference is 2(pi)r, I think. The radius is 3. 3 times 2 is 6. 6 times 3.14 is around 18, I think.
Answer:
4
Step-by-step explanation:
-3-(-7) is the same as -3+7, which is also the same as 7-3, which is equal to 4
Answer:
0.56 m/s
Step-by-step explanation:
The average speed of a body tells how fast is the body moving; it is calculated as:
where
d is the distance covered
t is the time elapsed
In this problem, we don't know the distance covered by Ben. Therefore, we will assume that it is 1 km:
d = 1 km = 1000 m
The time elapsed to cover this distance is:
Therefore, Ben's average speed is:
