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Expert: - 9/1/2011


Question
Picture To Problem 1
Picture To Problem 1
Hello. Would you mind checking to see if my answers are correct to these problems? Thank you so much.

Problem 1 - A simple dartboard has three areas… the main board has a radius of 11 inches, there is a circle with a radius of 5 inches, and the bullseye has a radius of 3 inches. What is the probability of a random dart landing inside the bullseye? Round to the nearest thousandth. (Hint: Use A = π r²)

My answer:
Bullseye = (pi)*3^2
Board = (pi)*11^2
P(land in bullseye) = [(pi)*9]/[(pi)*121] = 9/121 = 0.074

Problem 2 - Last fall, a gardener planted 87 iris bulbs. She found that only 72 of the bulbs bloomed in the spring.
1. Find the empirical probability that an iris bulb of this type will bloom. Give answer as a fraction in lowest terms.
2. How many of the bulbs should she plant next fall if she would like at least 88 to bloom?

My answer:
72/87 = 24/29
24/29x = 88
x = 106.33
107 bulbs

Problem 3 - A community 5K run will award $50 to the winner. 65 people enter the race, and they each pay an entry fee of $20. Assuming they are all equally likely to win, what is a fair price for the competition? Round to the nearest cent.

My answer:
Expectation = chance of win times entry fee - chance of loss times entry fee.
Expectation = (1/65)($20) - (64/65)($20)
Expectation = $0.31 - $19.69
Expectation = - $19.38
A fair entry price is $19.38

Problem 4 - According to the U. S. Census Bureau, the total 2008 U.S. population was 303,824,640. The chart below summarizes the 2008 population for five U.S. States.

State          2008 Population
Missouri          5,911,605
Pennsylvania      12,448,279
Tennessee         6,214,888
Utah          2,736,424
Washington        6,549,224

What is the probability that a randomly selected U.S. resident did not live in Washington?
Round solution to the nearest thousandth.

My answer:
= (total-Washington)/total
= (303824640-6549224)/303824640
= 0.978

Answer
Problem 3 was: A community 5K run will award $50 to the winner. 65 people enter the race, and they each pay an entry fee of $20. Assuming they are all equally likely to win, what is a fair price for the competition? Round to the nearest cent.

A correct answer:
They have a 1/65 chance of winning $50, so a fair entry price would be $50/65 = $0.77 = 77c.
They pay $20, and this is 20 - 0.77 = $19.23 over what is fair.

It should be noted that the people running the race will get 65*20 = $1,300,
and then would only have to give away $50, so the owners would be left with $1,250.
This means they are collecting an average of 25/26 of the money of each player as profit.

    Questioner's Rating
    Rating(1-10)Knowledgeability = 10Clarity of Response = 10Politeness = 10
    CommentScott, thanks so much for correcting me! I actually had $0.77 as my second answer, and changed it. Thanks for letting me know to change it, again.


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Scott A Wilson

Expertise

I can answer any question in general math, arithetic, discret math, algebra, box problems, geometry, filling a tank with water, trigonometry, pre-calculus, linear algebra, complex mathematics, probability, statistics, and most of anything else that relates to math. I can even tell you it takes me over 2,000 steps to go a mile, but is that relevant?

Experience

Experience in the area; I have tutored people in the above areas of mathematics for almost two years in AllExperts.com. I have tutored people here and there in mathematics since before I received a BS degree almost 25 years ago. In just two more years, I received an MS degree as well, but more on that later. I tutored at OSU in the math center for all six years I was there. Most students offering assistance were juniors, seniors, or graduate students. I was allowed to tutor as a freshman. I tutored at Mathnasium for well over a year. I worked at The Boeing Company for over 5 years. I received an MS degreee in Mathematics from Oregon State Univeristy. The classes I took were over 100 hours of upper division credits in mathematical courses such as calculus, statistics, probabilty, linear algrebra, powers, linear regression, matrices, and more. I graduated with honors in both my BS and MS degrees. Past/Present Clients: College Students at Oregon State University, various math people since college, over 7,500 people on the PC from the US and rest the world.

Publications
My master's paper was published in the OSU journal. The subject of it was Numerical Analysis used in shock waves and rarefaction fans. It dealt with discontinuities that arose over time. They were solved using the Leap Frog method. That method was used and improvements of it were shown. The improvements were by Enquist-Osher, Godunov, and Lax-Wendroff.

Education/Credentials
Master of Science at OSU with high honors in mathematics. Bachelor of Science at OSU with high honors in mathematical sciences. This degree involved mathematics, statistics, and computer science. I also took sophmore level physics and chemistry while I was attending college. On the side I took raquetball, but that's still not relevant.

Awards and Honors
I earned high honors in both my BS degree and MS degree from Oregon State. I was in near the top in most of my classes. In several classes in mathematics, I was first. In a class of over 100 students, I was always one of the first ones to complete the test. I graduated with well over 50 credits in upper division mathematics.

Past/Present Clients
My clients have been students at OSU, people nearby, friends with math questions, and several people every day on the PC, and you're probably make one more.

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