Redwood High School. Department of Mathematics
2015-2016 Advanced Algebra Stats wkst #1 .
Hard Worker's name:___________________________________
1) Kevin asked some of his friends how many hours they had worked during the previous
week at their after-school jobs. The results are shown below.
6 5 6 3 6 6 9 8 6 3 8 5
5 8 6 5 8 6 5 8 5 8 8 3
Construct a frequency distribution. Use 4 classes, a class width of 2 hours, and a lower limit
of 3 for
class 1.
Hours Frequency
Provide an appropriate response.
2) One purpose of displaying data graphically is to provide clues about trends. The given
values are weights (ounces) of steaks listed on a restaurant menu as "20 ounce porterhouse"
steaks. The weights are supposed to be 21 ounces because they supposedly lose an ounce
when cooked. Create a frequency distribution with 5 classes. Based on your distribution,
comment on the advertised "20 ounce" steaks.
17 20 21 18 20 20 20 18 19 19 20 19 21 20 18 20 20 19 18 19
Find the number of standard deviations from the mean. Round your answer to two decimal places.
3) The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10
inches. Last year there were 63 inches of snow. How many standard deviations from the
mean is that?
Solve the problem. Round results to the nearest hundredth.
4) Scores on a test have a mean of 70 and a standard deviation of 11. Michelle has a score of
48. Convert Michelle's score to a z-score.
5) The mean of a set of data is -3.82 and its standard deviation is 2.31. Find the z score for a
value of 3.99.
1
1)
2)
3)
4)
5)
Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual.
Consider a score to be unusual if its z-score is less than -2.00 or greater than 2.00. Round the z-score to the nearest tenth
if necessary.
6) A test score of 50.0 on a test having a mean of 69 and a standard deviation of 10.
6)
7) A body temperature of 99.5° F given that human body temperatures have a mean of 98.20°
F and a standard deviation of 0.62°.
7)
Find the area of the shaded region. The graph depicts the standard normal distribution with mean 0 and standard
deviation 1.
8)
8)
9)
9)
If z is a standard normal variable, find the probability.
10) The probability that z lies between 0 and 3.01
10)
11) The probability that z is less than 1.13
11)
12) The probability that z lies between -1.10 and -0.36
12)
13) The probability that z is greater than -1.82
13)
14) P(z > 0.59)
14)
15) Which of the following is true about the distribution of IQ scores?
A) The area under its bell-shaped curve is 2.
B) The area under its bell-shaped curve is 5.
C) The area under its bell-shaped curve is 10.
D) The area under its bell-shaped curve is 1.
2
15)
Answer Key
Testname: ADVALG S2 TEST #8 STATS WKSV1.SHORT
1)
Hours Frequency
3-4
3
5-6
13
7-8
7
9-10
1
2) Answers will vary. Possible answer: The frequency distribution shows that half of the cooked steaks are less than their
advertised weights.
3) 2.50 standard deviations above the mean
4) -2
5) 3.38
6) -1.9; not unusual
7) 2.1; unusual
8) 0.8708
9) 0.9656
10) 0.4987
11) 0.8708
12) 0.2237
13) 0.9656
14) 0.2776
15) D
3