Download Review Quiz

Review Quiz. If you cannot work these problems, you need to do some serious study to bring yourself up to speed.
1) The POPULATION of mice in Dr. McRae’s basement have the following weights in grams: 45, 52, 38, 27, 16,
10, 35. Enter your answers rounded to three decimal places. The mean weight of these mice is
_______________ . The standard deviation of mouse weights is _________________
a) Reference: D&S text, pp. 118 – 119 & 133 – 134. Similar problems 4.1, 4.3, 4.5
b) NOTE: For extensive data sets, insert the CD that came with your textbook. Cancel any mess that appears;
from Excel use “File Open” to go to “Data Sets,” thence to the appropriate chapter. Data sets appear by
names, and the name is given at the end of each problem statement. For example, question 4.3 uses the
dataset named “Citibank.”
2) A SAMPLE of ASU students had the following hourly wages: 2.50, 5.75, 3.00, 8.50, 2.50, 6.25, 9.00. Enter
your answers rounded to three decimal places. The mean wage in this sample was _________________ .
The standard deviation of hourly wages was _________________
a) Reference: D&S text, pp. 118 – 119 & 133 – 134. Similar problems 4.13, 4.17.
3) The scores on a standardized exam in statistics are normally distributed with  = 123 and  = 13.45. For each
of the following x values find the z value; round each answer to four decimal places.
a) x = 121, z = _________________
b) x = 142.67, z = _________________
c) x = 165, z = _________________
d) Reference: D&S text, pp. 140 – 143. Similar problem 4.19
4) For each of the following use the normsdist or normsinv function; give your answers to four decimal places.
a) If z = 1.25, find P(z > 1.25) _________________
b) Find P(z < -1.3476) _________________
c) Find P(z < 3) _________________
d) Find P(0.85 < z < 1.68) _________________
e) Find P(-1.23 < z < -0.3267) _________________
f) Reference: D&S text, pp. 266 – 280. Similar problems 7.13, 7.15
5) Find each of the following values of z using normsdist or normsinv. Round answers to four decimal places.
a) Find z0 such that P(z < z0) = 0.67 _________________
b) Find z0 such that P(z > z0) = 0.2 _________________
c) Find z0 such that only 20% of the z distribution is less than z 0 _________________
d) Find zC such that the middle 62% of the z distribution lies between −zC and +zC_________________
e) Similar problems 7.21, 7.23
6) The amount of diesel fuel needed for Big Joe the Truck Driver to drive from Tedium Town to Ennui City is
normally distributed with mean = 87 gals and st dev = 3 gallons. For each of the following, use normdist or
norminv and round answers to four decimal places.
a) What is the probability that Big Joe will use more than 92 gallons of diesel fuel on this run?
_________________
b) What is the probability that Big Joe will use between 82.5 and 86.7 gallons? _________________
c) What is the probability that Big Joe will use between 83 and 91 gallons on his run? _________________
d) On only twenty per cent of his runs, Big Joe will use this much or less fuel: _________________
e) How much fuel must Big Joe have in his tank to start if he wishes to have a 90% probability of finishing
his run? _________________
f) Similar problems 7.17, 7.19, 7.27, 7.29
Answers
Note: if you do not have exactly these answers, you have done something wrong.
1.
31.857
14.035
0.1057
0.0889
4. 0.9987
0.1512
0.2626
5.357
2.
2.768
0.4399
0.8416
5.
−0.8416
0.8779
−0.1487
1.4625
3.
3.1227
0.0478
0.3934
6. 0.8176
84.4751
90.8447