Posted by Laura on Sunday, January 3, 2010 at 4:41pm.
Of all U.S. fourth graders, 71% are assigned mathematics homework three or more times per week. If 5 fouth graders are randomly selected to be checked for this frequency of homework assignment during a randomly chosen week, find the probability that
A.) exactly one fourth grader was assigned homework three or more times that week
B.) no fourth grader was assigned homework three or more times that week
C.) at least one fourth grader was assigned homework three or more tiems that week

AP Statistics  bobpursley, Sunday, January 3, 2010 at 4:49pm
a)
NNNNY
NNNYN
NNYNN
NYNNN
YNNNN
so, there are five ways to sort the fourth graders
Pr(one)=5*.71*.29^4=.0251 check that.
b)Pr(none)=.29^5
c) Pr(at least one)=1Pr(none)

AP Statistics  sally, Friday, January 13, 2012 at 11:18am
A. .0251
B. .0020
C. None
Answer This Question
Related Questions
 Math Prob Stat  The amount of time a student spends completing homework per ...
 statistics  a mathematics professor wishes to analyze the relationship between ...
 statistics  First graders who misbehave in school may be more likely to be ...
 math  83 3rd graders 115 4th graders 150th graders all the 5th graders will be ...
 math  Ok, the problem says: a Middle school has 125 6th graders, 150 7th ...
 Math  The twoway table shows the number of fourth and fifth graders who do or...
 Math  There were 20 more fifth graders then fourth graders. 140 students from ...
 mATH  First graders who misbehave in school may be more likely to be regular ...
 statistics  A large school district would like to estimate the mean score for ...
 math214  Use the following data to justify the amount of time that you expect ...
More Related Questions