Answer: 0.421
Step-by-step explanation:
Heavy smoker = 20%
Light smoker = 30%
Non smokers = 50%
We can assume that the probability that a non-smoker is going to die in the next 5 years be y.
Since light smokers were twice as likely as nonsmokers to die during the five-year study, the probability will be:
= 2 × y = 2y
Probability for the Heavy smokers will be:= 2 × 2y = 4y
The expected number of people that will die for each in the next 5 years will be:
Non smoker:
= 50% × y
= 0.5 × y
= 0.5y
Light smoker:
= 30% × 2y
= 0.3 × 2y.
= 0.6y
Heavy smoker:
= 20% × 4y.
= 0.2 × 4y
= 0.8y
Total = 0.5y + 0.6y + 0.8y = 1.9y
The probability that the participant was a heavy smoker will be:
= 0.8y/1.9y
= 0.421
Answer:
Step-by-step explanation:
Surface area is finding the area of each face and adding them up. So a cube will have 6 faces, each of them a square. So find the area of one face and you can just add it 6 times. If the faces are not all the same you have to find them seperately. I won't do all of your questions, but let me know if you need help with a specific one
1) there are two trianglular faces and three rectangular ones. The triangles are the same so let's do those. They have the base and height of 4 and 3, so area of both will be .5*4*3 = 6, so together that makes 12. now the three rectangular sides. Right away you can see there is a 3 by 10 one and a 4 by 10 one. These ahve areas of 30 and 40 respectfully. The final face has one length of 10 but the last one is actually the last side of the right triangle faces. Use the Pythagorean theorem to find it, it word out to be 5. So now we know the last face is 10 by 5 which means an area of 50. So let's add them all together. 5 faces total with areas of 30, 40, 50, 6 and 6. Adding them together makes 136.
If you don't get how I did any of that let me know. In general it's a good idea to mark every face and then find what their sides are. I'd be happy to help with specific problems.
Now the second part, again I will do the second one because cones are little less intuitive. a cone has two faces, the circular base and the actual cone shape. the surface area of the cone shape is pi*r*L where r is the radius of the base and L is the length of one of the slanted sides. Now, let's find the area of the two faces. Area of a circle is pi*r^2 so that's pi*4^2 = 16*pi in number 2. Then the area of the cone part is pi*r*L = pi*4*14 = 56*pi. now we sum all the areas of the faces up and get 16*pi + 56*pi = 72*pi.
Again, I'm happy to answer specific questions, so let me know if you have any. just keep in mind what I told you so far, find each face, then find each face's area then sum them up. For cylinders the tubes turn into rectangles where one side is the length of the tube and the other is the circumference, while cones fave two faces, the circular base and the cone shape itself with an area of pi*r*L. if you want me to check your answers I will totally do that too.
Answer:
21
Step-by-step explanation:
Using<em> Simple Random Sampling</em>, we can estimate the sample size by the formula
where
n = sample size
Z = the z-score corresponding to the confidence level 99.5%
S = the assumed standard deviation = 3 seconds
e = margin of error = 2 seconds
<em>It is worth noticing that the higher the confidence level, the larger the sample should be.
</em>
The z-score corresponding to a confidence level of 99.5% can be obtained either with a table or the computer and equals
Z = 3.023
Replacing the values in our formula
So the size of the sample should be at least 21.
Answer:Find the distance between the parallel lines m and n whose equations are y = x + 4 and y = x - 6, respectively.
There are several ways to do this...here's one
Let (0, 4) be a point on the first line
Then.......a line with a negative reciprocal slope going through this point will have the equation :
y = -x + 4........so......we can find the intersection of this line with y = x - 6....set both equations equal
-x + 4 = x - 6 add x, 6 to both sides
10 = 2x divide both sides by 2
5 = x
So...using -x + 4, the y value at intersection = -1.......
So...we just need to find the distance from (0,4) to ( 5, -1) =
√[ (5)^2 + (4 + 1)^2 ] = 5√2 ≈ 7.07 units
Here's a pic....AB is the distance with A = (0,4) and B = (5, -1)
Step-by-step explanation:
