Answer:
50 pounds
Step-by-step explanation:
Dan and june mix two kind of feed for pedigreed dogs
Feed A worth is $0.26 per pound
Feed B worth is $0.40 per pound
Let x represent the cheaper amount of feed and y the costlier type of feed
x+y= 70..........equation 1
0.26x + 0.40y= 0.30×70
0.26x + 0.40y= 21.........equation 2
From equation 1
x + y= 70
x= 70-y
Substitutes 70-y for x in equation 2
0.26(70-y) + 0.40y= 21
18.2-0.26y+0.40y= 21
18.2+0.14y= 21
0.14y= 21-18.2
0.14y= 2.8
Divide both sides by the coefficient of y which is 0.14
0.14y/0.14= 2.8/0.14
y= 20
Substitute 20 for y in equation 1
x + y= 70
x + 20= 70
x= 70-20
x = 50
Hence Dan and june should use 50 pounds of the cheaper kind in the mix
Answer:
A. x > 21 2/3
Step-by-step explanation:
x is greater than 21 and two thirds
i did the math :]
Answer:
Equation : y = -0.5x − 8
Step-by-step explanation:
because i grabbed two points and plugged them in im not very good at explaining but im 99% sure thats right
It’s D
16/4 is 4 no more no less
The z score for a confidence level of 99% is 2.575.. You need to know this to complete this type of problem.. the other two commonly used confidence levels are 90% and 95% having z scores of 1.645 and 1.96 respectively. You need to memorize this!
To find the confidence interval, it will be defined as the sample mean plus/minus the margin of error.. Now to find the margin of error, divide the standard deviation of 12 by the square root of the number of elements in your sample(√250). Then take that result and multiply it by the Z score I mentioned above for a 99% confidence level.
In this case: the sample mean is 70 and the margin of error is approximately 1.95
So to calculate the confidence interval, do the following:
70 - 1.95 = 68.05 rounded to the nearest whole number is 68
70 + 1.95 = 71.95 rounded to the nearest whole number is 72
Looks like that would be the last choice. hope this helps.. it's been awhile since my work with statistics :-)
