Set up a ratio:
10 foot tall elephant / X shadow length = 15 foot tall statue / 18 foot shadow.
Cross multiply:
10 * 18 = X * 15
Simplify:
180 = 15x
Divide both sides by 15:
x = 180 / 15
x = 12
The elephants shadow was 12 feet long.
Answer:
- x +y = 500
- 0.65x +0.95y = 0.75(500)
- solution: (x, y) = (300, 200)
Step-by-step explanation:
A system of equations for the problem can be written using the two given relationships between quantities of brass alloys.
<h3>Setup</h3>
Let x and y represent the quantities in grams of the 65% and 90% alloys used, respectively. There are two relations given in the problem statement.
x + y = 500 . . . . . . quantity of new alloy needed
0.65x +0.90y = 0.75(500) . . . . . quantity of copper in the new alloy
These are the desired system of equations.
<h3>Solution</h3>
This problem does not ask for the solution, but it is easily found using substitution for x.
x = 500 -y
0.65(500 -y) +0.90y = 0.75(500)
(0.90 -0.65)y = 500(0.75 -0.65) . . . . . . subtract 0.65(500)
y = 500(0.10/0.25) = 200
x = 500 -200 = 300
300 grams of 65% copper and 200 grams of 90% copper are needed.
Answer:
a 120 cm^3
b 70 cm^3
Step-by-step explanation:
The volume of a right rectangular prism is given by
V = l*w*h
10 a V = 12*2*5
=120 cm^3
10 b V = 2.5 *8 *3.5
=70 cm^3
Answer:
Check the explanation
Step-by-step explanation:
(a)
P-value of income and size is 0.0003 and 0.0001 respectively. Both are less than 0.05 level of significance. So these are significant ot the model. Option D is correct.
(b)
The model is
House_size = -1.6335+0.4485*income + 4.2615*family_size -0.6517*school
Here we have income = 85600/1000 = 85.6
family_size = 6
school = 13
So the predicted house size is
House_size = -1.6335+0.4485*85.6 + 4.2615*6 -0.6517*13=53.855
the predicted house size (in hundreds of square feet) is 53.86. hence, option B is correct.
3)
Here we have income = 100000/1000 = 100
family_size = 10
school = 16
So the predicted house size is
House_size = -1.6335+0.4485*100 + 4.2615*10 -0.6517*16=75.40
Residual : observed value- predicted value = 70 - 75.40 = -5.40
Option C is correct.
