Together, they refinish 1/8th table per hour. Alone, the cousin does 1/12th table per hour. So:
1/8-1/12=1/24
1/1/24=24 hours for the person to finish the table by themself
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Answer:
a. x - cd = 0
b. d = 1 / 2
Step-by-step explanation:
d = 2
c = 7
a.
c is inversely proportional to d,
c ∝ 1 / d
This inversely proportional need to be removed by using a variation / variable.
Let the variable be " x ".
c = x / d
Multiply d on both sides,
cd = x
x = cd
Subtract cd on both sides,
x - cd = 0
Hence, the equation is " x - cd = 0 ".
b.
By using the equation,
x - cd = 0
Add cd on both sides,
x = cd
c = 17, d = 2
x = 17 * 2
x = 34
To find d, when c = 68.
x = cd
34 = 68 * d
Divide 68 on both sides,
34 / 68 = d
1 / 2 = d
d = 1 / 2
The initial temperature difference of 101-45 = 56 degees declined to 101-55 = 46 degrees in 8 minutes, We can write the exponential equation for the soda's temperature as
... T = 101 -56(46/56)^(t/8) . . . . where t is in minutes
After an additional 10 minutes, we have t=18, so the soda temperature will be
... T = 101 -56(46/56)^(18/8) ≈ 65.0 . . . degrees
After Sally had given 1/9 of her stamps to Andy, she had 280 stamps (since they now have equal shares). So 280 was 8/9 of what she started with, making the 1/9 she handed over equal to 280/8, that’s 35. And Andy was “under” by the same amount she was “over” an equal share, that’s 35 under matching her 35 over, which is 70 altogether.
By all means use algebra but you may find you can reason a word problem through in words.
Answer:
a. (0.6178, 5.1622)
b. (0.2637, 0.5592)
c.
Step-by-step explanation:
A.
For lead
n1 = 10
X1 = 2.89
S1 = 3.92
90% ci = 1-90%
= 0.10
TCritical = 1.833
Degree of freedom = 10-1 = 9
X1 +- TCritical * s/√n
= 2.88 +-1.833x3.92/√10
= 2.89+-2.2722
= 0.6178, 5.1622
Lead in water lies between this interval at 90% confidence level.
For cooper
n2 = 10
X2 = 0.4083
S2 = 0.2495
Alpha = 0.10
Df = 9
TCritical = 1.833
0.4083+-1.833*9.2495/√10
= 0.4084+-0.14462
= (0.26368, 0.55292)
Copper in water lies between this interval at 90% confidence level
C.
Underlying assumptions
The samples are randomly taken as well as independent. The sample size is not big enough. So it is approximately normally distributed.