Question 1 Consider the following binomial experiment:  A study in...

Question 1 Consider the following binomial experiment:  A study in a certain community showed that 8% of the people suffer from insomnia.  If there are 10,300 people in this community, what is the standard deviation of the number of people who suffer from insomnia?

a)75808.00

b)9476.00

c)824.00

d)40.60

e)27.53

f)None of the above.

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Question 2 Consider the following binomial experiment:  The probability that a fuse produced by a certain company will be defective is  ²⁄₅ .  If 500 fuses are produced each day, how many can weexpect to find each day that are defective ?

a)197

b)200

c)204

d)201

e)198

f)None of the above.

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Question 3 Let Z be a standard normal variable.  Find P(Z < -1.37).

a)0.0853

b)0.9032

c)0.9147

d)0.0968

e)0.0869

f)None of the above.

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Question 4 Let Z be a standard normal variable. Find P(Z > 2.23).

a)0.0139

b)0.0129

c)0.0228

d)0.9861

e)0.9871

f)None of the above.

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Question 5 Let Z be a standard normal variable.  Find P(-0.86 < Z < 2.25).

a)0.1980

b)0.7742

c)0.7884

d)0.7929

e)0.7898

f)None of the above.

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Question 6 Let Z be a standard normal variable.  Find the value of z if z satisfies P( -z< Z <z) = 0.7062.

a)1.05

b)0.50

c)1.50

d)-1.04

e)-0.54

f)None of the above.

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Question 7 Let Z be a standard normal variable.  Find the value of z if z satisfies P(Z >z) = 0.6331.

a)0.34

b)-0.34

c)-0.30

d)0.30

e)0.35

f)None of the above.

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Question 8 Let Z be a standard normal variable.  Find the value of z if z satisfies P(Z <z) = 0.9970.

a)2.70

b)3.00

c)-2.69

d)2.75

e)-2.75

f)None of the above.

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Question 9 Suppose X is a normal random variable with  μ = 40  and  σ = 20.  Find P(X > 105).

a)0.9994

b)0.9995

c)0.0007

d)0.9993

e)0.0006

f)None of the above.

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Question 10 Suppose X is a normal random variable with  μ = 35  and  σ = 10.  Find P(55.5 < X < 69.7).

a)0.0199

b)0.9769

c)0.9795

d)0.0190

e)0.0225

f)None of the above.

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Question 11 Laboratory experiment shows that the life of the average butterfly is normally distributed with a mean of 18.8 days and a standard deviation of 2 days.  Find the probability that a butterfly will live between 12.88 and 15.76 days.

a)0.0636

b)0.0628

c)0.0639

d)0.0653

e)0.0649

f)None of the above.

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Question 12 Endure All, a manufacturer of batteries claims that the lifetime of their batteries is normally distributed with a mean of 500 hours and a standard deviation of 40 hours. What is the probability that an Endure All battery selected at random will last more than 550 hours?

a)0.1587

b)0.8944

c)0.1056

d)0.1151

e)0.8849

f)None of the above.

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Question 13 Use the appropriate normal distribution to approximate the resulting binomial distributions.  A fair coin is tossed 130 times.  What is the probability of obtaining between 61 and 77 tails, inclusive?

a)0.7680

b)0.7358

c)0.7406

d)0.7709

e)0.7401

f)None of the above.

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Question 14 Use the appropriate normal distribution to approximate the resulting binomial distributions.  A convenience store owner claims that 55% of the people buying from her store, on a certain day of the week, buy coffee during their visit.  A random sample of 35 customers is made.  If the store owner's claim is correct, what is the probability that fewer than 22 customers in the sample buy coffee during their visit on that certain day of the week?

a)0.8413

b)0.7967

c)0.8238

d)0.7764

e)0.7224

f)None of the above.