<p>to make things short, please help me on multiple choice</p>
<p>3
7
11 (i got radical 1600, but i dont know how they got the 1664 part)</p>
<p>stupid probability! please answer before 9 PST or 10? i'm really desperate to figure out these q's. thx muchos</p>
<p>bump.. desperately waiting for an answer :l</p>
<p>i wish i could help(i have not taken stats) but it might help if you post the question.</p>
<p>Post the question
I'll explain the answer</p>
<p>ok here it is. just hoping u guys can help before i leave for the test at 11 </p>
<p>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?</p>
<p>answer's .00640 ?!?</p>
<p>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? </p>
<p>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 =(</p>
<p>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</p>
<p>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?</p>
<p>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!</p>
<p>Number 1: Make a probability tree.</p>
<p>All bags (p=1)
..Forbidden material (p=.001)
....Triggers (p=.97)</p>
<p>..Not Forbidden (p=.999)
....Triggers (p=.15)</p>
<p>So, the probability that forbidden material will actually be detected is (.97)(.001) = .00097. The probability that not forbidden material will be detected asa forbidden is (.999)(.15) = .14985. </p>
<p>.00097/(.14985+.00097) = .0064.</p>
<p>Number 2:
Group weight = 190*4 = 760
Group Standard Deviation of weight = sqrt[(10^2)(4)] = 20
normalcdf(800,10^10,760,20) = .0227.</p>
<p>You have to square standard deviation of each subject, add them together, then take the square root to get standard deviation of them all together.</p>
<p>Number 3:
This one doesn't make sense to me since (4^2)(10) = 160 and (40^2)(10) = 16000, not 1600. Regardless, since it seems that you're missing 64 (1664-1600), you probably forgot to use the box's standard deviation when calculating total standard deviation.</p>