SHOW WORK PLEASE, I WANT TO KNOW HOW TO DO IT.
6. A calculus exam had a mean of 75 and a
standard deviation of 6. If Sally had made a 78
on this exam, what is her z-score?
16. Find the following probabilities:
a. P(Z < ?1.82)
b. P(?1.68 < Z < 2.09)
c. P(Z > 0.56)
d. P(?0.52 < Z < 0.52)
e. P(?2.09 < Z <1.32)
f. P(Z > ?1.08)
18. Find the value of c that satisfies each of the
a. P(Z < c) = 0.0495
b. P(Z < c) = 0.8438
c. P(Z > c) = 0.0778
d. P(?c < Z < c) = 0.9774
2. The mean TOEFL score of international
students at a certain university is normally
distributed with a mean of 490 and a standard
deviation of 80. Suppose groups of 30 students
are studied. Find the mean and the standard
deviation for the distribution of sample means.