Answer:
0.7698
Step-by-step explanation:
If you call your random variable 
, then what you are looking for is
because you want the probability of being <em>between 87 and 123.</em>
We need a table with of the normal distribution. But we can only find the table with 
and 
. Because of that, first we need to <em>normalize </em>our random variable:
(you can always normalize your variable following the same formula!)
now we can do something similar to our limits, to get a better expression:
And we transform our problem to a simpler one:
(see Figure 1)
From our table we can see that 
(this is represented in figure 2).
Remember that the whole area below the curve is exactly 1. So we can conclude that 
(because 0.8849 + 0.1151 = 1). We also know the normal distribution is symmetric, then
.
FINALLY:
Angle 3 is 99 degrees.
Angle 2 is 61 degrees.
angle 1 is also 61 degrees.
Answer:
Elena invested $ 1,700 at 5%, $ 700 at 4%, and $ 600 at 3%.
Step-by-step explanation:
Given that Elena receives $ 131 per year in simple interest from three investments totaling $ 3000, and part is invested at 3%, part at 4% and part at 5%, and there is $ 1000 more invested at 5% than at 4%, to find the amount invested at each rate, the following calculations must be performed:
1500 x 0.05 + 500 x 0.04 + 1000 x 0.03 = 75 + 20 + 30 = 125
1600 x 0.05 + 600 x 0.04 + 800 x 0.03 = 80 + 24 + 24 = 128
1700 x 0.05 + 700 x 0.04 + 600 x 0.03 = 85 + 28 + 18 = 131
Therefore, Elena invested $ 1,700 at 5%, $ 700 at 4%, and $ 600 at 3%
Answer:
x=60.9°
Step-by-step explanation:
Given that the height of ball from the ground is 150ft
The base of the pole with the ball is 80 ft from where Trey is standing
Trey's horizontal line of sight is 6 feet above ground, then;
The height of ball from Trey's horizontal line of sight is;
150ft-6ft = 144ft
To find the angle x, assume a triangle with a base of 80 ft , a height of 144 ft and a slant height that represent the line of sight at an angle x
To get angle x , you apply the tangent of an angle formula where;
tan Ф°= length of opposite site of the angle/length of the adjacent side of the angle
tan x°= 144/80
tan x°= 1.8
x°= tan⁻(1.8)
x°=60.9°
