Question

The cost of unleaded gasoline in the Bay Area once followed an unknown distribution with a mean of $4.59 and a standard deviation of $0.10. Sbuteen gas stations from the Bay Area are randomly chosen. We are interested in the average cost of gasoline for the 16 gas stations. (1) The distribution to use for the average cost of gasoline for the 16 gas stations is: OAX - N(4.59, 0.1 OB X-(4.59, 0.1 OCX - N(4.59,0.1) OD:X-N(4.59, QUESTION 8 (2) What's the approximate probability that the average price for 16 gas stations is over $4.69? A slmost zero B. 0.1587 C.0.0943 Dunknown

Answer 1

1) option D is correct : since std error=σx̅=σ/√n

8)

for normal distribution z score =(X-μ)/σx
here mean=       μ=	4.59
std deviation   =σ=	0.100
sample size       =n=	16
std error=σx̅=σ/√n=	0.0250

probability =

P(X>4.69)

=

P(Z>4)=

1-P(Z<4)=

1-1=

0.0000

almost zero

3)

probability =

P(X<4.55)

=

P(Z<-2.19)=

0.0143

option A