18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
Answer:
1. z = -1.91429
The z score tells us that the head circumference of the girl with the down syndrome ( 44.5 cm) is 1.91429 standard deviations below the mean or average head circumference
2. 2.7792%
Step-by-step explanation:
1. Relative to the WHO data, what is this girls z-score?
z score formula is:
z = (x-μ)/σ, where
x is the raw score = 44.5 cm
μ is the population mean = 47.18cm
σ is the population standard deviation = 1.40cm
z = 44.5 - 47.18/1.40
z = -1.91429
What does the z score tell us?
The z score tells us that the head circumference of the girl with the down syndrome ( 44.5 cm) is 1.91429 standard deviations below the mean or average head circumference
2. Using the WHO data in a normal model, what percentage of the girls has a head circumference that is smaller than the girl with Down's Syndrome?
z score = -1.91429
Probability value from Z-Table:
P(z =-1.91429) = P(x<44.5) = 0.027792
Converting to percentage = 0.027792 × 100
= 2.7792%
Answer:
a)C
b)E
Step-by-step explanation:
a) You have to pick a vowel. There are three vowels and a total of 6 letters so it is 3/6 so the answer is C
b) Picking a card that is not T. None of the 6 letters are T so the probablity of picking a card with no T is 1. So the answer is E.
Answer:
For the length I think you meant 32, and if you did it is $14.40
If not and you meant length of 2 it is $0.90
Step-by-step explanation:
