Have I calculated this correctly?

The mean arrival rate of flights at O'Hare Airport in marginal weather is 195 flights per hour with a historical standard deviation of 13 flights. To increase arrivals, a new air traffic control procedure is implemented. In the next 30 days of marginal weather the mean arrival rate is 200 flights per hour. (a) Set up a right-tailed decision rule at α=.025 to decide whether there has been a significant increase in the mean number of arrivals per hour. (b) Carry out the test and make the decision. Is it close?Would the decision be different if you used α = .01? (c) What assumptions are you making, if any?

Flights
210 215 200 189 200 213 202 181 197 199
193 209 215 192 179 196 225 199 196 210
199 188 174 176 202 195 195 208 222 221 = 6,000

α =z.025 = 1.96, stdev=13, Uo=195, n=6000, x=200

(a)
Ho:u≤historical arrival rate
Ha:u>historical arrival rate
Reject Ho if z > 1.960

(b) z=
200 - 195 = 5 = 29.78
13÷√6000 = 0.1678
no the decision is not close
∝=.01 = 2.326 therefore no the decision would not be different

(c.) that it's a normal distribution

Hi, zetablue1!

Are you looking for dirrect answers to your questions or for someone to teach how to arrive at the correct answers yourself, please?

If the former is true, then please click on the following link to read the announcement that you're find there.

https://www.askmehelpdesk.com/math-s...-b-u-font.html

Thanks!

Quote:

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Originally Posted by Clough

Hi, zetablue1!

Are you looking for dirrect answers to your questions or for someone to teach how to arrive at the correct answers youself, please?

If the former is true, then please click on the following link to read the announcement that you're find there.

https://www.askmehelpdesk.com/math-s...-b-u-font.html

Thanks!

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It's clear from my post that I am not looking for someone to do my work for me but I am looking for some guidance if I am not understanding the concepts being taught.

If you get a z that high, be suspicious. Remember that beyond 3 is an outlier.

n isn't 6000. 6000 is the total flights during the 30 days, not the flights per hour. It was originally set up as flights per hour. So the samples have to be flights per hour, not total flights for the month. You have 30 samples. You sampled 30 days -- and that n already existed before you ever saw the outcome of the sampling.

Quote:

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Originally Posted by morgaine300

If you get a z that high, be suspicious. Remember that beyond 3 is an outlier.

n isn't 6000. 6000 is the total flights during the 30 days, not the flights per hour. It was originally set up as flights per hour. So the samples have to be flights per hour, not total flights for the month. You have 30 samples. You sampled 30 days -- and that n already existed before you ever saw the outcome of the sampling.

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Thanks I realized when I solved the problem and got an answer of 29 that something was not quite right. Again thank you. You always provide such great insight!

Er, thanks. :-) And you're welcome.