ap stat question on college board help!

k0w
Wed, 04 May 2005 02:42:39 +0000

ok here it is. just hoping u guys can help before i leave for the test at 11

all bags entering a research facility are screened. 97% of the bags that contain forbidden material trigger an alarm. 15% of the bags that do not contain forbidden material also trigger the alarm. if 1 out of every 1000 bags entering the building contains forbidden material, what is the probability that a bag that triggers the alarm will actually contain forbidden material?

answer’s .00640 ?!?

A summer resort rents rowboats to customers but does not allow more than four people to a boat. each boat is designed to hold no more than 800 pounds. suppose the distribution of adult males who rent boats, including their clothes and gear, is normal with a mean of 190 pounds and standard deviation of 10 pounds. if the weights of individual passengers are independent, what is the probability that a group of four adult male passengerse will exceed the acceptable weight limit of 800 pounds?

answer’s .023 ?!? i got .159 using normalcdf(800,10^10,190*4,10) since i know that you can’t add 40 to the standard deviation. maybe the variance? i dunno i gotta get some sleep =(

The attila Barbell company makes bars for weight lifting. the weights of the bars are independent and are normally distributed with mean 720 oz. standard deviation 4oz. bars shipped 10 in a box. box weighs mean 320, standard deviation 8 oz. weights of box filled with 10 are expectred to be normally distributed with mean 7520 oz and standard deviation

radical 1664 oz. i got 40, but i just rounded my answer to the nearest answer in the multiple choice. howd you get the 1664 part?

btw, i got a great program that tells u the equations and tests and explanations, but is ok to use it? my teacher said it was ok, but i wanna make sure. thanks muchos and thanks fro helping!