6y-8x=14(1)
Y=x+5(2)
6y-8x=14(3) ×1
Y-x=5(4)×6
6y-8x=14
6y-6x=30
-2x=16
X=8
Put x into equation 1
6y-8x=14
6y-8(8)=14
6y-64=14
6y=14+64
6y=78
6y=78
Y=13
The first standard deviation covers about 68% of the distribution in a normal curve. (34% higher, 34% lower than the mean). the second standard deviation covers 28% (14% between 1st and 2nd SD above the mean, 14% between 1st and 2nd SD below the mean). In our case
1 Standard deviation = 27 hours (we will approximate to 25 hours)
Mean = 2,000
This means that 34% of the distribution is between 1975 and 2000 hours (within 1 standard deviation below the mean)
2,000- 2,050 covers the range within 50 hours above the mean.
50 hours is roughly 2 standard deviations. The second standard deviation (standard deviation between 1 and 2) covers around 14% on each side of the distribution.
50 hours is roughly 2 standard deviations, which means we add 34% + 14% = 48%.
The range of 1,975 - 2,050 hours covers 34% of the distribution below the mean and 48% of the distribution above the mean.
This means that the probability that the light bulb will last somewhere within this range is 34% + 48% = 82%
The closest answer is 79%. The difference can be explained by the fact that, for simplicity, we approximated the standard deviation to be ~25 hours instead of the real standard deviation of 27 hours.
Answer:
C
Step-by-step explanation:
we are just multiplying 6.1x0.12 it gives us 0.732 simple
Answer:
Please check explanations
Step-by-step explanation:
Firstly, we calculate the area of the floor
That is the product of the sides
= 300 * 540 = 162,000 cm^2
What is left is to calculate the area of a tile
Since the tile is also rectangular, the area of each tile will be;
60 * 30 = 1,800 cm^2
Since we have both areas, we can now get the number of tiles needed to cover the floor
We can get this by dividing the area of the floor by the area of a tile
This is;
162,000/1,800 = 90
This means that 90 tiles will cover the floor
The cost of a tile
is £4.25
The cost of 90 tiles will be ;
£4.25 * 90 = £382.5
from here, we can see that the £400 is more than £382.5
So we can conclude that she has enough to spend on tiles
Answer:
10+2+1=13
Step-by-step explanation:
We already know that he is making ten cups originally. So if we add p(2) to that, we get 12 and then we add a(1) to it, we get 13