Answer:
There is a 90.32% probability that the cake was baked by Doug.
Step-by-step explanation:
We have these following probabilities:
A 70% probability that Doug bakes the cake.
A 30% probability that Jeremy bakes the cake.
A 40% probability that a cake baked by Doug gets a thumbs up.
A 10% that a cake baked by Jeremy gets a thumbs up.
One cake was selected at random on 10/01/2014 and got a "thumbs up".
1. Find the probability that the cake was baked by Doug.
The probability that a baked cake gets a thumbs up is:

Of those, 0.7*0.4 = 0.28 are baked by Doug.
So the probability is:

There is a 90.32% probability that the cake was baked by Doug.
1. The area of the photograph is:
A=LxW
A is the area of the photograph (A=54 in²).
L is the lenght of the photograph (L=12-4x).
W is the widht of the photograph (W=12-2x)
2. When you substitute these values into the formula A=LxW, you obtain:
A=LxW
54=(12-4x)(12-2x)
3. When you apply the distributive property, you have:
54=144-24x-48x+8x²
8x²-72x+144-54=0
4. Finally, you obtain a quadratic equation for the area of the photo:
8x²-72x+90=0
5. Therefore, the answer is:
8x²-72x+90=0
- Discriminant Formula: b² - 4ac, with a = x^2 coefficient, b = x coefficient, and c = constant
So firstly, using our equation plug in the values into the discriminant formula and solve as such:
(-7)² - 4 × 3 × 4
49 - 48
1
So our discriminant is 1. <u>Since 1 is positive and a perfect square, this means that there are 2 real, rational solutions.</u>
<span>The following characteristics of experiments are not also characteristics of surveys:
- The first one is </span><span>B. The study compares two or more treatments (possibly including "no treatment").
- The other one is </span><span>D. The study involves one or more treatment groups and a control group.</span>