W2A3
Quiz
1. For a particular sample of 56 scores on a psychology exam, the following results were obtained.
First quartile = 67 Third quartile = 91 Standard deviation = 9 Range = 48
Mean = 75 Median = 80 Mode = 81 Midrange = 74
Answer each of the followi
Binomial Distributions
Law of large numbers, in statistics, the theorem that, as the number of identically distributed,
randomly generated variables increases; their sample mean (average) approaches their
theoretical mean.
Binomial distribution is one of
W6A2
Quiz
Week 1
1: (A) Classify the following as an example of nominal, ordinal, interval, or ratio level of measurement, and state
why it represents this level: salaries of the CEOs of seven regional banks
(B) Determine if this data is qualitative or qu
W6A1
Discussion Questions
Question 1:
Describe what a Type I and Type II error would be for the following null hypothesis:
: There is no difference between chemotherapy and radiation treatments.
Type I: There is no difference between chemotherapy and rad
W5A3
Quiz
1: Assume that the mean SAT score in Mathematics for 11th graders across the nation is 500, and
that the standard deviation is 100 points. Find the probability that the mean SAT score for a
randomly selected group of 150 11th graders is between
W5A2
Mixed Problems
1: Consider a population with = 73.6 and = 5.38. (4 points)
a. Calculate the z-score for = 72.7 from a sample of size 45.
b. Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why
no
W5A1
Discussion Questions
Question 1:
If we wish to have a 98% confidence interval, what would be the value of /2? Show how you
arrived at this answer.
A = 1 - 0.98 = 0.02
0.02 / 2 = 0.01
0.5000 0.01 = 0.49 = 2.33
Question 2:
If a population has a standar
W4A3
Quiz
1. If the random variable z is the standard normal score and P(z > a) < 0.5, then a > 0. Why
or why not?
(Points : 3)
Yes, because under the properties of the standard normal distribution the total area is
equal to 1 and if a was zero or less th
W4A2
Mixed Problems
1. A set of 50 data values has a mean of 35 and a variance of 25.
I. Find the standard score (z) for a data value = 26.
II. Find the probability of a data value > 26.
(Points : 4)
I.
II.
Z=
value mean
= 26 35 = -1.76
Standard deviation
W4A1
Discussion Questions
Question 1:
If the random variable z is the standard normal score and a > 0, is it true that P(z > -a) = P(z < a)?
Why or why not?
If you assume that z = 0 and you change a to equal 5 then this is what your problem would look
lik
W3A4
Quiz
1: A bag of colored blocks contains the following assortment of colors:
red (18), blue (22), orange (15), purple (5), green (15), and yellow (5).
Construct the probability distribution for x.
(Points : 6)
Color of the block
x
Red
Blue
Orange
Pur
W3A2
Mixed Problems
1. The scatter plot below shows the relationship between the day of a particular month a stock was valued and
the price of the stock in dollars. The horizontal axis represents the day of the month. Use this graph to
answer the question
W3A1
Discussion Questions
Question 1:
Explain why this is or is not a probability distribution,
x
1
2
P(x)
0.2
0.1
3
0.4
4
0.2
This is not a probability distribution because as a rule the sum of the probability must equal one
and this one adds up to P(x)
Blocking and Surveys
Blocking can help reduce the effect of variation among experimental subjects. The subjects
share a characteristic that might affect response to the treatment.
The process of a blocked and unblocked experiment explained through the pro