Applied 40S April 14, 2009

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The cast of my non-stop entertainment by Xanboozled Binomial Distributions

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Introduction to Binomial Distributions.

Transcript of Applied 40S April 14, 2009

Page 1: Applied 40S April 14, 2009

The cast of my non-stop entertainment by Xanboozled

Binomial Distributions

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An orange producer who calls himself Doctor Juice grows an exclusive variety of oranges which are sorted into three categories and sold at different prices.

The diameters of the oranges are distributed normally with a mean of 84 mm and a standard deviation of 12 mm.

(a) What percent of the oranges are sorted into the small category?

(b) What is the minimum diameter (rounded to the nearest millmeter) of a Jumbo Orange?

(c) What is the expected income from 2000 unsorted oranges,

Description Size Price per orangeSmall less than 75mm 12 centsJumbo largest 12% 45 centsRegular all others 35 cents

HOMEWORK

Hand this in now

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The life of a toaster is found to be normally distributed with a mean life of 4.7 years and a standard deviation of 0.9 years. The manufacturer of the toaster will replace free of charge any toaster that malfunctions while under warranty. For how many months should the manufacturer guarantee the toasters if no more than 10 percent of them are to be replaced? Will the manufacturer likely replace 10 percent of the toasters?

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The cast of my non-stop entertainment by Xanboozled

Binomial Distributions

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In some probability experiments, there are exactly two possible outcomes. For example:

• When flipping a coin, you get heads or tails. When flipping a coin 200 times, what is the probability of getting heads exactly 101 times? (The answer is 5.58 percent)

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In some probability experiments, there are exactly two possible outcomes. For example:

• When answering a question on a multiple choice test, your answer will be right or wrong. What is the probability of getting 50 percent of the answers correct if there are four choices for each question, and you guess each answer?

• When flipping a coin, you get heads or tails. When flipping a coin 200 times, what is the probability of getting heads exactly 101 times? (The answer is 5.58 percent)

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In some probability experiments, there are exactly two possible outcomes. For example:

• When a manufacturer guarantees a toaster for one year, the toaster will work fine or fail in one year. The manufacturer knows that, on average, 5 percent of the toasters fail. What is the probability that the manufacturer will have to replace 120 or more toasters in a year when 2000 toasters are sold?

• When answering a question on a multiple choice test, your answer will be right or wrong. What is the probability of getting 50 percent of the answers correct if there are four choices for each question, and you guess each answer?

• When flipping a coin, you get heads or tails. When flipping a coin 200 times, what is the probability of getting heads exactly 101 times? (The answer is 5.58 percent)

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In some probability experiments, there are exactly two possible outcomes. For example:

• When a manufacturer guarantees a toaster for one year, the toaster will work fine or fail in one year. The manufacturer knows that, on average, 5 percent of the toasters fail. What is the probability that the manufacturer will have to replace 120 or more toasters in a year when 2000 toasters are sold?

• When answering a question on a multiple choice test, your answer will be right or wrong. What is the probability of getting 50 percent of the answers correct if there are four choices for each question, and you guess each answer?

• When flipping a coin, you get heads or tails. When flipping a coin 200 times, what is the probability of getting heads exactly 101 times? (The answer is 5.58 percent)

Binomial Distributions

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Type of Distributions...

Example: graph the distribution that shows what can happen when a 6-sided die is thrown.

Uniform Distribution: data may be discrete or continous. Every outcome in the experiment is equally likely.

Uniform (Probability) Distribution

Probabilities of outcomes when rolling a six sided

die.

No data between 0 and 1.

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Type of Distributions...

Normal Distributions: Data is continous (height, weight, time, etc.) when certain experiments are carried out many, many, many times the probability graph of the data tend to be "bell shaped" this is known as the Normal Curve.

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How many girls are there in a family of four children.

Find the probability of there being 0, 1, 2, 3, or 4 girls in the family.

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Type of Distributions...

Binomial Distribution: data is discrete (# of heads when ten coins are tossed, # of spades in a 13 card hand , etc.). When a binomial experiment is conducted many, many, many times a portion of the related histogram approaches the shape of the normal curve.

Experimental Binomial (Probability) Distribution

Theoretical Binomial (Probability) Distribution

Probability of the number of girls in a family of four.

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Theoretical Binomial (Probability) Distributionbinompdf(trials, p, x [this is optional])

trials = number of trials p = P(success) x = specific outcome

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The weights of babies born in a certain hospital average 8 lb 1 oz, with a standard deviation of 12 oz. Assume that the weights are normally distributed.

(c) Find the weight, W, such that the percentage of babies with a birth weight less than W is 25 percent.

(b) Find the weight, W, such that the percentage of babies with a birth weight greater than W is 60 percent.

(a) Find the percentage of babies with a birth weight between 7 and 9 pounds.

HOMEWORK

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A college aptitude test is scaled so that its scores approximate a normal distribution with a mean of 500 and standard deviation of 100.

(b) Find the score x, such that 76 percent of the students have a score less than x.

(a) Find the probability that a student selected at random will score 800 or more points. HOMEWORK

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Forty students measured the width of the gym, and wrote their measurements in centimetres, rounded to the nearest cm. The measurements are recorded on the table below.

Draw a histogram of the data. Using the properties of a Normal Distribution, determine if the data is approximately normal.

2251 2249 2250 2247 2253 2248 2249 22532254 2247 2250 2253 2248 2255 2249 22492250 2251 2252 2250 2249 2250 2247 22502250 2252 2253 2255 2254 2248 2248 22422249 2245 2251 2246 2250 2246 2251 2246

HOMEWORK