Answer choices for pt c (c) Why should you expect the probability of part (b) to
ID: 3219688 • Letter: A
Question
Answer choices for pt c
(c) Why should you expect the probability of part (b) to be higher than that of part (a)? (Hint: Consider the standard deviations in parts (a) and (b).)
The standard deviation of part (b) is ( smaller than, larger than, the same as) part (a) because of the (smaller, same, larger) sample size. Therefore, the distribution about x is (the same, narrower, wider) .
Explanation / Answer
a)mean = 12
here std error =std deviation/(n)1/2 =0.87
P(12<X<14) =P((12-12)/0.87<Z<(14-12)/0.87)=P(0<Z<2.3094)=0.9895-0.5=0.4895
b)mean =12
std error =std deviation/(n)1/2 =0.73
P(12<X<14) =P((12-12)/0.73<Z<(14-12)/0.73)=P(0<Z<2.7285)=0.9968-0.5=0.4968
c)The standard deviation of part (b) is smaller than part (a) because of thelarger) sample size. Therefore, the distribution about x is narrower