Answer:
He wont foul out with probability 0.9093
Step-by-step explanation:
The total number of fools he picked is a Binomial ditribution noted by X with parameters p = 0.05 and N = 48. The mean of this random variable is μ = np = 48*0.05 = 2.4 and the variance is σ² = np(1-p) = 2.4*0.95 = 2.28, hence its standard deviation is σ = √2.28 = 1.51.
Note that, if approximate probability is asked, we could just approximate X with a Normal random variable with mean 2.4 and standard deviation 1.51 (this can be done because of the central limit theorem). We will calculate the probability manually. He wont foul out if he picks 0,1,2,3 or 4 fouls, thus
As a consecuence, he wont foul out with probability 0.9093.
Answer:
100 degrees and 70 degrees
Step-by-step explanation:
180 - 10 = 170
with a ratio of 7:10
7x + 10x = 170
17x = 170
x = 170/17
x = 10
one angle in 100 degrees and the other is 70 degrees
There are two of them.
I don't know a mechanical way to 'solve' for them.
One can be found by trial and error:
x=0 . . . . . 2^0 = 1 . . . . . 4(0) = 0 . . . . . no, that doesn't work
x=1 . . . . . 2^1 = 2 . . . . . 4(1) = 4 . . . . . no, that doesn't work
x=2 . . . . . 2^2 = 4 . . . . . 4(2) = 8 . . . . . no, that doesn't work
x=3 . . . . . 2^3 = 8 . . . . . 4(3) = 12 . . . . no, that doesn't work
<em>x=4</em> . . . . . 2^4 = <em><u>16</u></em> . . . . 4(4) = <em><u>16</u></em> . . . . Yes ! That works ! yay !
For the other one, I constructed tables of values for 2^x and (4x)
in a spread sheet, then graphed them, and looked for the point
where the graphs of the two expressions cross.
The point is near, but not exactly, <em>x = 0.30990693...
</em>If there's a way to find an analytical expression for the value, it must involve
some esoteric kind of math operations that I didn't learn in high school or
engineering school, and which has thus far eluded me during my lengthy
residency in the college of hard knocks.<em> </em> If anybody out there has it, I'm
waiting with all ears.<em>
</em>
Answer:
<h3>t = 15d</h3>
Step-by-step explanation:
You must first know that 1 week = 7days
If Sophie practices the piano 105 minutes in 1 week, this can be expressed as;
105 minutes = 7days
to calculate the total time t that she practices for any number of days, d, we will say;
t minutes = d days.
Solving both expression;
105 minutes = 7days
t minutes = d days.
Cross multiply;
7 * t = 105 * d
7t = 105d
Divide both sides by 7;
7t/7 = 105d/7
t = 15d
Hence a proportional equation for t in terms of d that matches the context is expressed as t = 15d
B because the multiplication has different signs
