Answer:
D. 720cm squared is the answer
Answer:
Car = 10 miles/hour
Bus = 20 miles/hour
Step-by-step explanation:
Here,
Let, the value of the speed of the bus = X
the value of the speed of the car = 2X - 30 (As the speed of the car is 30mph slower than twice)
According to the question,
2X - 20 = 2*(2x-30)
or, 2X - 20 = 4X-60
or, 2X = 40
x = 20
Therefore, the speed of the bus, x = 20 miles/hour
So, the speed of the car is (2*20-30) mph = (40 - 30) mph = 10 miles/hour.
Answer:
We accept H₀
Step-by-step explanation:
Normal Distribution
size sample n = 69
sample mean 18.94
standard deviation 8.3
Is a one tailed-test to the left we are traying of find out is we have enough evidence to say that the mean is less than 20 min.
1.-Test hypothesis H₀ ⇒ μ₀ = 20
Alternative hypothesis Hₐ ⇒ μ₀ < 20
2.- Critical value
for α = 0.1 we find from z Table
z(c) = - 1.28
3.-We compute z(s)
z(s) = [ ( μ - μ₀ ) / (σ/√n) ⇒ z(s) = [( 18.94 - 20 )*√69)/8.3]
z(s) = ( -1.06)*8.31/8.3
z(s) = - 1.061
4.- We compare
z(c) and z(s) -1.28 > -1.061
Then z(c) > z(s)
z(s) in inside acceptance region so we accept H₀
The annual return percentages will be evaluated using the formula:
A=P(1+r/100)^n
where:
A=amount
P=principle
r=rate
n=time
a] A=$500, P=$400, n=1 years
500=400(1+r)^1
solving for r we shall obtain:
1.25=1+r
hence
r=1.25-1
r==0.25
annual rate of investment is 25%
b] A=2500+100=$2600, P=$ 2000, n=1 year
hence
2600=2000(1+r)^1
2600/2000=1+r
1.3=1+r
r=1.3-1
r=0.3
annual rate of investment is 30%
