2)For 2000 patients, a blood-clotting time was normally distributed with a mean of 8 seconds and a standard deviation of 3 seconds. What percent had blood-clotting times between 5 and 11 seconds?

Question

2)For 2000 patients, a blood-clotting time was normally distributed with a mean of 8 seconds and a standard deviation of 3 seconds. What percent had blood-clotting times between 5 and 11 seconds? 
A)68% 
B)34% 
C)49/5% 
D)47/5% 
I chose A

4)A music teacher wants to determine the music performances of students. A survey of which group would produce a random sample? 
A)students in the school band 
B)students attendeing the annual jazz concert 
C)students in every odd-numbered homeroom 
D)every other player on the baseball roster 
is it A?

DanH · Answer

2) A is correct
4): I think the point of this question is that the teacher wants a RANDOM sample of students. The only choice that would really give her a random sample would be C. All others are biased.

BIAO · Answer

POITS A,B, AND C ARE COLLINEAR .AB=7CM BC =13CM WHATIS AC ANSWER