Difference between revisions of "TDSM 2.1"

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(Created page with "Let <math>A</math> is the event that people like butter <math>\\Rightarrow P(A) = 0.8</math> '''Probability''' <br>2-1. Suppose 80% of people like peanut butter, 89% like j...")
 
 
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Let <math>A</math> is the event that people like butter <math>\\Rightarrow P(A) = 0.8</math>
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<i>A</i>: event that people like butter
  
 +
<i>B</i>: event that people like jelly
  
'''Probability'''
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<math>P(B|A) = \frac{P(A\cap B)}{P(A)} = \frac{0.78}{0.8} = 0.975</math>
 
 
<br>2-1.
 
Suppose 80% of people like peanut butter, 89% like jelly, and 78% like both. Given that a randomly sampled person likes peanut butter, what is the probability that she also likes jelly?
 
 
 
[[TDSM 2.1|(Solution 2.1)]]
 
 
 
<br>2-3.
 
Consider a game where your score is the maximum value from two dice. Compute the probability of each event from <math>\{1, \ldots, 6\}</math>
 
 
 
[[TDSM 2.3|(Solution 2.3)]]
 
 
 
<br>2-5.
 
If two binary random variables <i>X</i> and <i>Y</i> are independent, is <math>\bar{X}</math> (the complement of <i>X</i>) and <i>Y</i> also independent? Give a proof or a counterexample.
 
 
 
[[TDSM 2.5|(Solution 2.5)]]
 
 
 
 
 
'''Statistics'''
 
 
 
<br>2-7.
 
Construct a probability distribution where none of the mass lies within one <math>\sigma</math> of the mean.
 
 
 
[[TDSM 2.7|(Solution 2.7)]]
 
 
 
<br>2-9.
 
Show that the arithmetic mean equals the geometric mean when all terms are the same.
 
 
 
[[TDSM 2.9|(Solution 2.9)]]
 
 
 
 
 
'''Correlation Analysis'''
 
 
 
<br>2-11.
 
What would be the correlation coefficient between the annual salaries of college and high school graduates at a given company, if for each possible job title the college graduates always made:
 
<ol type="a">
 
<li>5,000 dollars more than high school grads?</li>
 
<li>25% more than high school grads?</li>
 
<li>15% less than high school grads?</li>
 
</ol>
 
 
 
[[TDSM 2.11|(Solution 2.11)]]
 
 
 
<br>2-13.
 
Use data or literature found in a Google search to estimate/measure the strength of the correlation between:
 
<ol type="a">
 
<li>Hits and walks scored for hitters in baseball.</li>
 
<li>Hits and walks allowed by pitchers in baseball.</li>
 
</ol>
 
 
 
[[TDSM 2.13|(Solution 2.13)]]
 
 
 
 
 
'''Logarithms'''
 
 
 
<br>2-15.
 
Show that the logarithm of any number less than 1 is negative.
 
 
 
[[TDSM 2.15|(Solution 2.15)]]
 
 
 
<br>2-17.
 
Prove that
 
<math>x \cdot y = b^{(\log_b x + \log_b y)}</math>
 

Latest revision as of 16:47, 11 September 2017

A: event that people like butter

B: event that people like jelly

[math]P(B|A) = \frac{P(A\cap B)}{P(A)} = \frac{0.78}{0.8} = 0.975[/math]