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Stuck on 3a. Im not too sure on what a point estimate is. I thought it would just be 10.01ounces given in the question.

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Reply 1

Smaug123

Original post by cooldudeman

Stuck on 3a. Im not too sure on what a point estimate is. I thought it would just be 10.01ounces given in the question.

I think you're right, but the question is a bit odd. What answer do you have for the probability that it's the true mean? (That answer is why I think the question is odd.)

Reply 2

cooldudeman

Original post by Smaug123

I think you're right, but the question is a bit odd. What answer do you have for the probability that it's the true mean? (That answer is why I think the question is odd.)

Im not really sure. Im thinking that it would be the reverse of finding the confidence interval. Id guess its 50% because of the mean being in the middle of the normal dist curve.

So on normal tables for P(Z<0)

(edited 10 years ago)

Reply 3

Smaug123

Original post by cooldudeman

What is Probability(mu = 10.01) where mu follows a normal distribution? (It does, since the sum of normally distributed random variables is normally distributed.)

Reply 4

sophieshoesmith

OUNCES! How many years old is that question!
I guess its asking whats probabilitity that 10.005>u>10.015 and thats a width of .01/sqr(0.0004) (ie 0.01/0.006 ie 1.5 standard deviations)

so 0.75 s.ds. each side of the mean does cover about 50%

(edited 10 years ago)

Reply 5

cooldudeman

Original post by Smaug123

What is Probability(mu = 10.01) where mu follows a normal distribution? (It does, since the sum of normally distributed random variables is normally distributed.)

So 'point' means its equal to it im guessing

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Reply 6

Smaug123

Original post by cooldudeman

So 'point' means its equal to it im guessing

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P(Z = 0) = 0. The probability that a continuous random variable takes any given value is 0.

Reply 7

cooldudeman

Original post by Smaug123

P(Z = 0) = 0. The probability that a continuous random variable takes any given value is 0.

I thought continuity corrections apply?

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Reply 8

Smaug123

Original post by cooldudeman

I thought continuity corrections apply?

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Continuity corrections apply to discrete distributions being approximated by continuous ones. We are only considering normal distributions here.

Reply 9

cooldudeman

Original post by Smaug123

Continuity corrections apply to discrete distributions being approximated by continuous ones. We are only considering normal distributions here.

So the probability is 0%? Thats so strange

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Reply 10

Smaug123

Original post by cooldudeman

So the probability is 0%? Thats so strange

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It's because of the fact that

\int_a^a f(x) dx = 0

Reply 11

cooldudeman

Original post by Smaug123

It's because of the fact that

\int_a^a f(x) dx = 0

i was kinda saying strange because it makes the other questions on 3 strange to do. for 3b, to find the standard error, you do the Z value multiplied by the standard deviation but that would be zero...