The decimal number is 0.9
Answer:
12 sq mi
Step-by-step explanation:
base times height divided by 2
7x²=9+x
so
for
0=ax²+bx+c
so
7x²=9+x
mins 9 from both sides and minus x
7x²-1x-9=0
a=7
b=-1
c=-9
so the 4th one
Answer:
(x, y) = (3, 3)
Step-by-step explanation:
Subtract double the second equation from the first.
(2x +3y) -2(x +y) = (15) -2(6)
y = 3 . . . . . . . . simplify
Use the second equation to find x.
x = 6 -y = 6 -3 = 3
The values of x and y are both 3.
Answer:
38%
Step-by-step explanation:
Given that X,the hours per week the music student practice follow a normal distribution.
X:N(8,4)
We have to find the percentage of students who practice between 6 and 10 hours.
6<x<10 implies converting to z
We know z = (x-mean)/sigma = (x-8)/4
Hence 6<x<10 is equivalent to (6-8/4)<Z<(10-8/4)
= |z|<0.5
From std normal table we find this area equals = 0.1915+0.1915
=0.3830 = 0.38 (rounded off)
Hence required percentage = 0.38x100 = 38%
