In: Statistics and Probability
The StatCrunch data set for this question contains the data
measurements described in Question 11. (H0 :
µ1 - µ2 ≤ 0
HA : µ1 - µ2 > 0)
Assume that the two samples are dawn from independent, normally
distributed populations that have different standard deviations.
Use this data set and the results from Question 11 to calculate the
p-value for the hypothesis test. Round your answer to three
decimal places; add trailing zeros as needed.
The p-value = [S90PValue].
Using the result from Question 12, identify the appropriate decision for the hypothesis test in Question 11, along with its interpretation. Use α = 0.01.
Fail to reject H0. There is insufficient evidence to support the original claim that the mean amount of Strontium-90 collected from City 1 residents' teeth is greater than the mean amount collected from the residents of City 2.
Reject H0. There is insufficient evidence to support the original claim that the mean amount of Strontium-90 collected from City 1 residents' teeth is greater than the mean amount collected from the residents of City 2.
Fail to reject H0. There is insufficient evidence to reject the original claim that the mean amount of Strontium-90 collected from City 1 residents' teeth is greater than the mean amount collected from the residents of City 2.
Reject H0. There is sufficient evidence to support the original claim that the mean amount of Strontium-90 collected from City 1 residents' teeth is greater than the mean amount collected from the residents of City 2.
city1 city 2
104 117 ""
86 73 ""
121 100 ""
119 85 ""
101 84 ""
104 107 ""
213 110 ""
144 111 ""
290 105 ""
100 133 ""
275 101 ""
145 209 ""
Given that,
mean(x)=150.1667
standard deviation , s.d1=70.25
number(n1)=12
y(mean)=111.25
standard deviation, s.d2 =34.7017
number(n2)=12
null, Ho: u1 <= u2
alternate, H1: u1 > u2
level of significance, α = 0.01
from standard normal table,right tailed t α/2 =2.718
since our test is right-tailed
reject Ho, if to > 2.718
we use test statistic (t) = (x-y)/sqrt(s.d1^2/n1)+(s.d2^2/n2)
to =150.1667-111.25/sqrt((4935.0625/12)+(1204.20798/12))
to =1.7206
| to | =1.7206
critical value
the value of |t α| with min (n1-1, n2-1) i.e 11 d.f is 2.718
we got |to| = 1.72055 & | t α | = 2.718
make decision
hence value of |to | < | t α | and here we do not reject
Ho
p-value:right tail - Ha : ( p > 1.7206 ) = 0.05665
hence value of p0.01 < 0.05665,here we do not reject Ho
ANSWERS
---------------
null, Ho: u1 <= u2
alternate, H1: u1 > u2
test statistic: 1.7206
critical value: 2.718
decision: do not reject Ho
p-value: 0.05665
we do not have enough evidence to support the claim that City 1
residents' teeth is greater than the mean amount collected from the
residents of City 2.