E) 12 minutes
A normal curve has approximately 95% of graph between mean - 2sd and mean + 2sd
So 95% of the times will be between 0 and 12 minutes. 6 - 2x3 to 6 + 2x3
2.5% will take over 12 minutes
Strangely 2.5% will also take less than 0 minutes to process which shows the normal curve is not perfect in this example.
4/5÷2/3=x
4/5×3/2=x
12/10=x
1 1/5=x
Answer: 7:3
Step-by-step explanation:
15 chairs are red
35 are blue
35:15
Simplifies to
7:3
Answer:
n = π/6, π/4, 3π/4, 5π/6
Step-by-step explanation:
sin(3n) − sin n = cos(2n)
Use double and triple angle formulas:
(3 sin n − 4 sin³ n) − sin n = 1 − 2 sin² n
2 sin n − 4 sin³ n = 1 − 2 sin² n
4 sin³ n − 2 sin² n − 2 sin n + 1 = 0
Factor by grouping:
2 sin² n (2 sin n − 1) − (2 sin n − 1) = 0
(2 sin² n − 1) (2 sin n − 1) = 0
Solve:
2 sin² n − 1 = 0
2 sin² n = 1
sin² n = 1/2
sin n = √2/2
n = π/4, 3π/4
2 sin n − 1 = 0
2 sin n = 1
sin n = 1/2
n = π/6, 5π/6
