BIOSTATS EXAM 2 HW QUESTIONS WITH ALL CORRECT
& VERIFIED ANSWERS (UPDATED TO PASS)
If you fold a normal curve, each half would fit perfectly on top of the other. This characteristic is
known as _______________. Correct answer-symmetry
In order to say that a distribution is positively skewed, which of the following must be true? (choose
one or more) Correct answer-Right tail must be longer than the left
Which of the following is a measure of how asymmetric your data is? Correct answer-Skewness
What is the term associated with how flat or peaked a distribution appears? Correct answer-
Kurtosis
If the mean of a set of scores is greater than the median, what can be said about the distribution?
Correct answer-Positively skewed
True or False, the mean for a set of z scores is zero. Correct answer-True
If you want to calculate a z score for a test where your individual score was 24, what other
information must you know? (choose one or more) Correct answer--mean
-standard deviation
Under which condition(s) would you use a t-score instead of a z-score? Correct answer--Your
sample size is less than 30
-You do not know the population standard deviation
Under the normal curve, approximately what percent of scores fall between and -1 to +1 standard
deviations around the mean? Correct answer-68%
-Empirical Rule
If you know the z score (z), standard deviation(s) and mean (M), what formula would you use to
compute the raw score (X)? Correct answer-X = z(s) + M
-Z score formula
In a normal distribution with a sample size of 60, a mean of 100 and a standard deviation of 15, what
is the probability that a score will be 100 or lower? Correct answer-50%
In a normal distribution with a sample size of 45, a mean of 100, and a standard deviation of 15,
what is the probability that a score will be 118 or higher? Correct answer-11.51%
Given that the population of women's height has a mean of 63.6 inches and a standard deviation of
2.5 inches, answer the following questions:
What is the z-score corresponding to a height of 70 inches? Correct answer-(70-63.6)/2.5
=2.56
What is the range of height for 68% of women? Correct answer-+/- one standard deviation
63.6+ 2.5= 66.1
63.6- 2.5= 61.1
-61.1-66.1
, What is the probability that a woman will have a height greater than 64.5 inches? Correct answer-
(64.5-63.6)/2.5
=.36
64.06-100
=35.94%
What is the probability that a woman will have a height between 60 inches and 65 inches? Correct
answer-(Get probability percentages for both values and add them together)
=63.74%
When using table B.1 in your text to determine the area under the curve which of the following are
true? (choose one or more) Correct answer--If you need the area above a positive z score you have
to subtract the area provided from 50
-The area between the mean and the z score is the same for a positive or negative z score
-If you need the area below a negative z score you have to subtract the area provided from 50
Which of the following methods may be helpful in determining the area under the curve? (choose
one or more) Correct answer--draw a diagram and shade the area of interest
-Understand how to read your area under the curve table
-Stick with one version of the area under the curve table
In a normal distribution with a mean of 78 and a standard deviation of 7, what is the probability that
a score will be greater than 82? Correct answer-(82-78)/7
=0.57
71.56-100
=28.43%
In a normal distribution with a mean of 78 and a standard deviation of 7, what is the probability that
a score will be between 71 and 85? Correct answer-68.26%
-Zscores are -1 and 1 it is one SD away from the mean
True or False, a finding can be statistically significant, but not clinically significant. Correct answer-
True
In order to determine whether or not you will reject the null hypothesis, the test statistic should be
compared to which of the following? Correct answer-Critical value
The process of hypothesis testing starts with the assumption that Correct answer-the null
hypothesis is true
Which of the following represents a nondirectional research hypothesis? Correct answer-H1: x
bar1 ≠ x bar2
Which of the following symbols represents the null hypothesis? Correct answer-H0
Which of the following symbols represents the first research hypothesis? Correct answer-H1
A hypothesis is basically a(n) Correct answer-Educated guess
True or False, the alternative hypothesis states that there is no difference/no effect. Correct
answer-False
& VERIFIED ANSWERS (UPDATED TO PASS)
If you fold a normal curve, each half would fit perfectly on top of the other. This characteristic is
known as _______________. Correct answer-symmetry
In order to say that a distribution is positively skewed, which of the following must be true? (choose
one or more) Correct answer-Right tail must be longer than the left
Which of the following is a measure of how asymmetric your data is? Correct answer-Skewness
What is the term associated with how flat or peaked a distribution appears? Correct answer-
Kurtosis
If the mean of a set of scores is greater than the median, what can be said about the distribution?
Correct answer-Positively skewed
True or False, the mean for a set of z scores is zero. Correct answer-True
If you want to calculate a z score for a test where your individual score was 24, what other
information must you know? (choose one or more) Correct answer--mean
-standard deviation
Under which condition(s) would you use a t-score instead of a z-score? Correct answer--Your
sample size is less than 30
-You do not know the population standard deviation
Under the normal curve, approximately what percent of scores fall between and -1 to +1 standard
deviations around the mean? Correct answer-68%
-Empirical Rule
If you know the z score (z), standard deviation(s) and mean (M), what formula would you use to
compute the raw score (X)? Correct answer-X = z(s) + M
-Z score formula
In a normal distribution with a sample size of 60, a mean of 100 and a standard deviation of 15, what
is the probability that a score will be 100 or lower? Correct answer-50%
In a normal distribution with a sample size of 45, a mean of 100, and a standard deviation of 15,
what is the probability that a score will be 118 or higher? Correct answer-11.51%
Given that the population of women's height has a mean of 63.6 inches and a standard deviation of
2.5 inches, answer the following questions:
What is the z-score corresponding to a height of 70 inches? Correct answer-(70-63.6)/2.5
=2.56
What is the range of height for 68% of women? Correct answer-+/- one standard deviation
63.6+ 2.5= 66.1
63.6- 2.5= 61.1
-61.1-66.1
, What is the probability that a woman will have a height greater than 64.5 inches? Correct answer-
(64.5-63.6)/2.5
=.36
64.06-100
=35.94%
What is the probability that a woman will have a height between 60 inches and 65 inches? Correct
answer-(Get probability percentages for both values and add them together)
=63.74%
When using table B.1 in your text to determine the area under the curve which of the following are
true? (choose one or more) Correct answer--If you need the area above a positive z score you have
to subtract the area provided from 50
-The area between the mean and the z score is the same for a positive or negative z score
-If you need the area below a negative z score you have to subtract the area provided from 50
Which of the following methods may be helpful in determining the area under the curve? (choose
one or more) Correct answer--draw a diagram and shade the area of interest
-Understand how to read your area under the curve table
-Stick with one version of the area under the curve table
In a normal distribution with a mean of 78 and a standard deviation of 7, what is the probability that
a score will be greater than 82? Correct answer-(82-78)/7
=0.57
71.56-100
=28.43%
In a normal distribution with a mean of 78 and a standard deviation of 7, what is the probability that
a score will be between 71 and 85? Correct answer-68.26%
-Zscores are -1 and 1 it is one SD away from the mean
True or False, a finding can be statistically significant, but not clinically significant. Correct answer-
True
In order to determine whether or not you will reject the null hypothesis, the test statistic should be
compared to which of the following? Correct answer-Critical value
The process of hypothesis testing starts with the assumption that Correct answer-the null
hypothesis is true
Which of the following represents a nondirectional research hypothesis? Correct answer-H1: x
bar1 ≠ x bar2
Which of the following symbols represents the null hypothesis? Correct answer-H0
Which of the following symbols represents the first research hypothesis? Correct answer-H1
A hypothesis is basically a(n) Correct answer-Educated guess
True or False, the alternative hypothesis states that there is no difference/no effect. Correct
answer-False
