The Statistics Question and Problem Solved

QUESTION 1
t = 2.02, df = 150, α= .05
The t is statistically significant for a two-tailed test, at the specified alpha
TRUE or FALSE?
t stat 2.02
df 150
α 0.05
p value 0.04516359
Decisio
n
Significant as p value less
than α
Hence, statement is TRUE
QUESTION 2
State the critical (tabled) value of t that would be used to reject the null hypothesis of
equality of population means, for an independent groups t-test under the following
conditions:
H1: μ1 ≠ μ2; n1 = 20, n2 = 20; α = .05
df =n1 + n2 – 2= 20 + 20 -2 = 38.
The distribution is two tailed from the alternative hypothesis.
n1 20
n2 20
significanc
e
0.05
df 38
t critical 2.024394
Thus the t critical value for an independent groups is 2.024 approximately.
Q U E S T I O N 3
State the critical (tabled) value of t that would be used to reject the null hypothesis of
equality of population means, for an independent groups t-test under the following
conditions:
Hi: μ1 > μ2; n1 = 30, n2 = 30; α = .01
The test is one tailed from the “>” sign in the alternative hypothesis. The critical t value is
calculated using excel as given below.

n1 20
n2 20
significance 0.01
df 38
t critical -2.42857
Hence, the t critical value is -2.42857.
QUESTION 4 CHOOSE ONE ANSWER
For which of the following situations is the independent groups t-test appropriate?
A The independent variable (IV) is type of stimulation for premature infants
(auditory vs. visual vs. tactile); the dependent variable (DV) is cardiac
responsiveness
B. The IV is parental role within couples (mother versus father); the DV is degree of
bonding with the infant
C. The IV is sex (men vs. women); the DV is compliance vs. noncompliance with a
medication regimen
D. The IV is infant birthweight (low birthweight vs. normal birthweight); the DV is
number of days absent from school in first grade
Independent group t-test is appropriate for two groups of samples which are not
related. Hence, independent groups t-test appropriate for option A, C and D as in
these cases the samples are not related.
QUESTION 5 CHOOSE ONE ANSWER
For which of the following situations is the dependent groups t-test (paired t-
test) appropriate?
A. The IV is Time (Baseline and one-month post intervention); the DV is blood
pressure
B. The IV is time since incarceration (1 month vs. 3 months vs. 6 months); the
DV is body weight
C. The IV is age group (teenagers vs. young adults); the DV is attitudes toward
condom use
D. The IV is nap therapy for narcoleptics (before vs. after treatment); the DV is
unplanned naps the following week (had vs. did not have an unplanned nap)