Answer:
[0.16316 , 0.27684]
Step-by-step explanation:
0.22 +/- 1.96(0.029)
0.22 +/- 0.05684
[0.16316 , 0.27684]
Answer:
BC= 20 units
Step-by-step explanation:
Since ∆ ABC is an equilateral triangle, all the sides are equal in length.
AC= BC
=>-y+23= 6y+2
=>-y-6y= 2-23
=>-7y= -21
=>y= 21/7
=>y= 3
BC = 6y+2 = 6(3)+2 = 18+2 = 20 units
Trigonometry as taught is mostly about memorizing two lousy triangles, namely half a square and half an equilateral triangle. This one is half an equilateral triangle.
The respective opposite sides of the 30/60/90 triangle are in ratio 
A sine of √3/2 is an opposite of √3 and a hypotenuse of 2, so opposite and hypotenuse of the 60 degree angle. (It's the mama bear, in the middle, just right.)

In the end you just have memorize the two tired triangles of trig.
Answer:
8.0622577483
you can take it from here...
200,000 tons. There are 2000 lbs in a ton so do 4,000,000,000 divided by 2000 and you get 200,000