Econ 391 Exam 1 questions & answers
graded A+
null hypothesis - correct answer ✔✔= always on null
tentative assumption about a population parameter
alternative hypothesis - correct answer ✔✔research hypothesis
opposite of the null hypothesis
what you want to prove
Standard deviation - correct answer ✔✔have to calculate variance first
then square root
T/F the arithmetic mean is the middle of the data set - correct answer ✔✔False
median- middle value
mean- average
Is it possible for a data set to have no mode? - correct answer ✔✔yes, if there are no
observations that occur more than once.
if it's greater than or equal to..... - correct answer ✔✔subtract 1- (z-score)
Which of the following is not a characteristic of the normal
probability distribution?
, A) The mean of the distribution can be negative, zero, or posit
ive.
B) The distribution is symmetrical.
C) The mean, median, and mode are equal.
D) The standard deviation must be one. - correct answer ✔✔D
this is for STANDARD normal distribution
For the standard normal probability distribution, the area to t
he
left of the mean is:
A) 0.50
B) any value between zero to one.
C) -0.50
D) 1.00 - correct answer ✔✔A)
normal probability is symmetrical
A negative value of z indicates:
A) the number of standard deviations an observation is below th
e mean.
B) a mistake has been made in computations, since z cannot be n
egative.
C) the number of standard deviati
ons an observation is above th
e mean.
D) the data has a negative mean. - correct answer ✔✔A)
Z is normalized so that z=0 is the mean
graded A+
null hypothesis - correct answer ✔✔= always on null
tentative assumption about a population parameter
alternative hypothesis - correct answer ✔✔research hypothesis
opposite of the null hypothesis
what you want to prove
Standard deviation - correct answer ✔✔have to calculate variance first
then square root
T/F the arithmetic mean is the middle of the data set - correct answer ✔✔False
median- middle value
mean- average
Is it possible for a data set to have no mode? - correct answer ✔✔yes, if there are no
observations that occur more than once.
if it's greater than or equal to..... - correct answer ✔✔subtract 1- (z-score)
Which of the following is not a characteristic of the normal
probability distribution?
, A) The mean of the distribution can be negative, zero, or posit
ive.
B) The distribution is symmetrical.
C) The mean, median, and mode are equal.
D) The standard deviation must be one. - correct answer ✔✔D
this is for STANDARD normal distribution
For the standard normal probability distribution, the area to t
he
left of the mean is:
A) 0.50
B) any value between zero to one.
C) -0.50
D) 1.00 - correct answer ✔✔A)
normal probability is symmetrical
A negative value of z indicates:
A) the number of standard deviations an observation is below th
e mean.
B) a mistake has been made in computations, since z cannot be n
egative.
C) the number of standard deviati
ons an observation is above th
e mean.
D) the data has a negative mean. - correct answer ✔✔A)
Z is normalized so that z=0 is the mean
