Answer:
A
Step-by-step explanation:
idk
1)
x + 2y = 21
+ -x + 3y = 29
--------------------------
5y = 50
y = 10
x + 2(10) =21
x = 1
2)
6x + 6y = 30
+ 15x - 6y = 12
-------------------------------
21x = 42
x = 2
6(2) + 6y = 30
6y = 18
y = 3
Answer:
10 km/h
Step-by-step explanation:
I'm not really sure about this but no ones answering your question and I wanna help.
So basically to calculate the average speed you need to divide the distance travelled by time taken
But you do not have the distance traveled. But it is mentioned that it takes u 30 minutes to walk from home to school when walking at 5 km/h so to find the distance all you have to do is... 30 x 5 = 150 km
Now that we have the time and distance all we have to do is find the average speed.
Average Speed = distance ÷ time
So 150 ÷ 15 = 10 km/h
Answer: - 0.28
Explanation:
1) Expected value: is the weighted average of the values, being the probabilities the weight.
That is: ∑ of prbability of event i × value of event i.
In this case: (probability of getting 2 or 12) × (+6) + (probability of gettin 3 or 11) × (+2) + (probability of any other sum) × (-1).
2) Sample space:
Sum Points awarded
1+ 1 = 2 +6
1 + 2 = 3 +2
1 + 3 = 4 -1
1 + 4 = 5 -1
1 + 5 = 6 -1
1 + 6 = 7 -1
2 + 1 = 3 +2
2 + 2 = 4 -1
2 + 3 = 5 -1
2 + 4 = 6 -1
2 + 5 = 7 -1
2 + 6 = 8 -1
3 + 1 = 4 -1
3 + 2 = 5 -1
3 + 3 = 6 -1
3 + 4 = 7 -1
3 + 5 = 8 -1
3 + 6 = 9 -1
4 + 1 = 5 -1
4 + 2 = 6 -1
4 + 3 = 7 -1
4 + 4 = 8 -1
4 + 5 = 9 -1
4 + 6 = 10 -1
5 + 1 = 6 -1
5 + 2 = 7 -1
5 + 3 = 8 -1
5 + 4 = 9 -1
5 + 5 = 10 -1
5 + 6 = 11 +2
6 + 1 = 7 -1
6 + 2 = 8 -1
6 + 3 = 9 -1
6 + 4 = 10 -1
6 + 5 = 11 +2
6 + 6 = 12 +6
2) Probabilities
From that, there is:
- 2/36 probabilities to earn + 6 points.
- 4/36 probabilites to earn + 2 points
- the rest, 30/36 probabilities to earn - 1 points
3) Expected value = (2/36)(+6) + (4/36) (+2) + (30/36) (-1) = - 0.28
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
