Answer:
7.5 ft³/min
Step-by-step explanation:
Let x be the depth below the surface of the water. The height, h of the water is thus h = 10 - x.
Now, the volume of water V = Ah where A = area of isosceles base of trough = 1/2bh' where b = base of triangle = 4 ft and h' = height of triangle = 1 ft. So, A = 1/2 × 4 ft × 1 ft = 2 ft²
So, V = Ah = 2h = 2(10 - x)
The rate of change of volume is thus
dV/dt = d[2(10 - x)]/dt = -2dx/dt
Since dV/dt = 15 ft³/min,
dx/dt = -(dV/dt)/2 = -15 ft³/min ÷ 2 = -7.5 ft³/min
Since the height of the water is h = 10 - x, the rate at which the water level is rising is dh/dt = d[10 - x]/dt
= -dx/dt
= -(-7.5 ft³/min)
= 7.5 ft³/min
And the height at this point when x = 8 inches = 8 in × 1 ft/12 in = 0.67 ft is h = (10 - 0.67) ft = 9.33 ft
Let's say we had a sample of 100 people. We'll split them into two equal groups of 50 each. The two groups will be the treatment and control groups. The treatment group, aka experimental group, is where the actual drug is given. The control group is where the fake drug is given. People in the control group must not know the pill is fake. For more info, check out the placebo effect. In short, this is when a person takes a fake pill and thinks they get better, and that positive mentality helps them actually get better.
If both the treatment and control groups improve (on average) together, then that means the fake pill is just as good as the real thing. Consequently, it means the real pill isn't effective at all. If on the other hand the experimental group does better overall compared to the control group, then we can see that the real pill is doing what it's intended to do. Of course, there are a lot of complicated factors involved, as there is with anything dealing with medicine. I haven't mentioned anything about side effects or things of that nature. In this simplified viewpoint of the world, we're only considering the one factor of whether or not the drug clears up the psoriasis on the skin.
To make things fair, it's best to randomly generate numbers so that you randomly assign people into each group. That way you have representative samples. Also, when drawing the sample of 100 people, make sure that's as random as possible to help represent the population as best as possible. The fact that the people in the control group not knowing that they are taking the fake pill means we have a single blind experiment. A double blind experiment is when even the researchers are not sure who is taking the real pill vs the fake pill. Double blind experiments are encouraged to prevent the researcher's bias from affecting the results.
To keep participants from knowing whether or not they are in the control group, the common solution is to provide a sugar pill. The pill will not cause any side effects and will not cause any improvements to health. It's simply sugar. To the participant, it seems like the real thing since they can't taste the difference or detect anything seems different.
Answer:
100.7%
Step-by-step explanation:
Since the interest is compounded quarterly, and there are 4 quarters per year, that would leave us with 32 quarters total where interest is acquired. Now, we need to find the interest rate, that would be required in order to end up with 420 dollars after 32 quarters.
We can setup a formula using our period of time and the money he invested into the bank:
We can divide 340 from both sides, and simplify the right side to 21 divided by 17:
Taking the 32th root of 21/17 is equal to 1.00662, which is equal to 100.0662%. To the nearest tenth of a percent, this is equal to 100.7%.
Answer: 75(2) OR 25(6)
Step-by-step explanation:75+75 = 150 OR 25+25+25+25+25+25=150
Answer:
308 cm³
Step-by-step explanation:
The volume (V) of a rectangular prism ( cuboid ) is
V = lbh ( l is the length, b the breadth and h the height )
Here l = 11, b = 7 and h = 4, thus
V = 11 × 7 × 4 = 308 cm³
