Suppose x grams of 8% solution should be mixed to make 100 g of 3% solution.
here we shall have:
the amount of 3% solution in the 100 g will be:
3/100*100=3 grams
the the equation will be, 8% of what quantity becomes 3g?
(8/100)*x=3
hence solving for x we shall have:
0.08x=3
x=3/0.08
x= 37.8 grams
The implication of this is that, when you have 37.5 grams of 8% solution, that will contain 3 of pure chemical and hence when you add more solvent on top of 37.5 g until you reach 100g, that will be 3% solution.
Answer:
So we can find this probability:

And then since the interest is the probability that the mean diameter of the sample shafts would differ from the population mean by more than 0.3 inches using the complement rule we got:

Step-by-step explanation:
Let X the random variable that represent the diamters of interest for this case, and for this case we know the following info
Where
and
We can begin finding this probability this probability
For this case they select a sample of n=79>30, so then we have enough evidence to use the central limit theorem and the distirbution for the sample mean can be approximated with:

And the best way to solve this problem is using the normal standard distribution and the z score given by:
And we can find the z scores for each limit and we got:
So we can find this probability:

And then since the interest is the probability that the mean diameter of the sample shafts would differ from the population mean by more than 0.3 inches using the complement rule we got:

Answer:

Step-by-step explanation:
y′′ + 4y′ − 21y = 0
The auxiliary equation is given by
m² + 4m - 21 = 0
We solve this using the quadratic formula. So

So, the solution of the equation is

where m₁ = 3 and m₂ = -7.
So,

Also,

Since y(1) = 1 and y'(1) = 0, we substitute them into the equations above. So,


Substituting A into (1) above, we have

Substituting B into A, we have

Substituting A and B into y, we have

So the solution to the differential equation is

Use mathpapa.com or cymath.com
To find how many cm are in a ft, you have to use the method of unit rate:
so we know that 12 in. equals a ft. so,
1 ft
------
12 in.
and 2.25 cm equals an in. so,
1 in.
-------
2.54cm
then we put the rates together and get:
1ft 1 in.
---- X -------................we cancel out the in. units and get:
12 in. 2.54 cm
Solve and get 1 ft = 30.48 cm