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theopenstudyowl
 one year ago
Easy Statistics, solved some, but need some help too! Thanks!
theopenstudyowl
 one year ago
Easy Statistics, solved some, but need some help too! Thanks!

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theopenstudyowl
 one year ago
Best ResponseYou've already chosen the best response.0John is an expert horseshoe thrower who only misses 15% of the time. Choose the expression that correctly represents the probability John will miss fewer than 50 times if he throws 400 horseshoes. normalcdf(E99,50,60,7.14) normalcdf(50,E99,60,7.14) normalpdf(E99,50,400,7.14) normalpdf(E99,50,60,7.14) normalcdf(E99,50,400,7.14)

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1Are you familiar with binomial probability distributions?

perl
 one year ago
Best ResponseYou've already chosen the best response.0first find the mean and st. dev for a binomial distribution mean = n*p st. dev = sqrt( np (1p))

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1well you'll start there and then use a normal distribution to approximate it. What's odd is that they didn't account for the continuity correction factor. Oh well Anyways, we are given n = 400 trials p = 0.15 is the probability of success q = 1p = 10.15 = 0.85 is the probability of failure use these values to compute the mean mu and standard deviation sigma mu = n*p = 400*0.15 = 60 sigma = sqrt(n*p*q) = sqrt(400*0.15*0.85) = 7.14

theopenstudyowl
 one year ago
Best ResponseYou've already chosen the best response.0wow thanks guys, now I can do the rest of these problems now that i have an example!

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1dw:1433453221391:dw

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1The binomial distribution can be approximated using a normal distribution with mean mu = 60 and standard deviation sigma = 7.14 (approximate) dw:1433453286569:dw the mean determines the center while the standard deviation tells you how spread out things are

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1so if we are asked what is the probability that John "will miss fewer than 50 times if he throws 400 horseshoes." it's essentially asking "what is the area under the normal distribution curve to the left of 50" dw:1433453396591:dw

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1what expression would you type into the calculator to answer the question "what is the area under the normal distribution curve to the left of 50"

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1that's what i would go for, but remember all of your answer choices are either "normalpdf" or "normalcdf"

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1so that's why it seems like they want to use the normal distribution to approximate the binomial distribution
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