Question

1 2 3 4 5 6 7 Question 6 of 8 (1 point) Attempt 2 of Unlimited 6.2 Section Exercise sample of size 7 will be drawn from a normal population with mean 63 and standard deviation 15. Use the TI-84 Plus calculator. a) Is it appropriate to use the normal distribution to find probabilities for x? (b) Find the probability that I will be between 53 and 73. Round the answer to at least four decimal places. (e) Find the 83rd percentile of X. Round the answer to at least two decimal places. (a) Is it appropriate to use the normal distribution to find probabilities for x? Yes O NO (b) The probability that x will be between 53 and 73 is . rd (c) The 83 percentile of x is N

Answer 1

a)

Yes, normal distribution is appropriate here to find the probabilities of x bar.

b)

o = Z n - X

mean = 63, S.D = 15

When X = 53

z = (53 - 63) / 15 = -10/15 = -0.67

which gives 0.2514 in the z-table.

When X = 73

z = (73 - 63) /15 = 10/15 = 0.67

which gives 0.7486 in the z-table.

Therefore, the area between them will be (0.7486 - 0.2514), which is 0.4972.

P = 0.4972

c)

The 83rd percentile can be calculated using the dataset here.