For a standardized psychology examination intended for psychology majors, the historical data show that scores have a mean of 520 and a standard deviation of 180. the grading process of this year's exam has just begun. the average score of the 35 exams graded so far is 518. what is the probability that a sample of the 35 exams will have a mean score of 518 or more if the exam scores follow the same distribution as in the past? carry your intermediate computations to at least four decimal places. round your answer to at least three decimal places.

step-by-step explanation:

it's 15

1. sometimes

2.   never

3   .08c = 7.50+.05c   250 pages

step-by-step explanation:

1.   sometimes

the theoretical probability of rolling a 1 is 1/6.   perhaps you got really lucky and never rolled a 1   in those 60 times.   your experimental probability is 0.   or perhaps you rolled a 1   20 times.   your experimental probability is 20/60 is 1/3.     it really just depends on how you rolled in that experiment.

2.   never

the probability of the event occurring is 1.   that is being 100 % sure it will happen.   that is the maximum amount of confidence we have.

3.   no customer card cost:   .08 times number of pages

customer card cost:   7.50 + .05 times number of pages

we want to find when it costs the same amount, so we will set these equal

let c = number of pages

.08c = 7.50+.05c

subtract .05c from each side

.08c-.05c = 7.5+.05c-.05c

.03c=7.5

divide each side by .03

.03c/.03 = 7.5/03

c =250  

the cost is the same at 250 pages

answer: it is a.,b.,d.

step-by-step explanation: