Answer:
0.38% probability that the sample contains exactly two defective parts.
Step-by-step explanation:
For each part, there are only two possible outcomes. Either it is defective, or it is not. The probabilities for each part being defective are independent from each other. So we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
In this problem we have that:

What is the probability that the sample contains exactly two defective parts?
This is 


0.38% probability that the sample contains exactly two defective parts.
The answer is -16 - 10i.
Using the distributive property on the first part, we have:
-2i*7--2i*4i + (3+i)(-2+2i)
-14i+8i² +(3+i)(-2+2i)
Using FOIL on the last part,
-14i+8i²+(3*-2+3*2i+i*-2+i*2i)
-14i+8i²-6+6i-2i+2i²
-10i+8i²-6+2i²
Since we know that i = -1,
-10i+8(-1)-6+2(-1)
-10i-8-6-2
-16-10i
Answer:
A bag of pop corn costs $8, and each Pretzel costs $4.25.
Step-by-step explanation:
Let
be the price of popcorn, and
the price of Pretzels. If the girl bought 2 bags of popcorn and 5 Pretzels and it cost her $37.25, we have the equation
<em>(this says that the cost of 2 popcorn bags plus 5 pretzels equals $37.25)</em> .
And, since Zoe bought 8 popcorn bags and 9 Pretzels with a total price of $102.25, we get the equation
<em> (this says that the cost of 8 popcorn bags plus 9 Pretzels equals $102.25).</em>
Thus, we have two equations
1. 
2. 
and we solve them by first multiplying equation (1) by 4:
,
and then subtracting it from equation (2):

Now we put this value of
into equation (1) and get:

and we solve for
to get:


Therefore, a bag of popcorn costs $8, and each Pretzel costs $4.25.
Answer:
1. A ring of grass with an area of 314 yd squared surrounds a circular flower bed. Find the width x of the ring of grass.
The radius of the circular flower bed = 10 yd.
2. Harriet has 80 m of fencing materials to enclose three sides of a rectangular garden. She will use the side of her garage as a border for the fourth side. Find the width x of the garden if its area is to be 700 m squared.
3. Sid cuts four congruent squares from the corners of a 30-in.-by-50-in. rectangular piece of cardboard so that it can be folded to make a box. Find the side length s of the squares, given that teh area of the bottom of the box is 200 in squared.
Step-by-step explanation:
Let
T--------> the total of the lot
we know that
a buyer purchase=0.25T+0.50T------> 0.75T
<span> lot still available for purchase=T-[0.75T]-----> 0.25T
T----------> 100%
0.25T----> x
x=0.25T*100/T------> x=25%
the answer is
25%</span>