Listed below are time intervals​ (min) between eruptions of a geyser. Assume that the​ "recent" times are within the past few​ years, the​ "past" times are from around 20 years​ ago, and that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Does it appear that the mean time interval has​ changed? Is the conclusion affected by whether the significance level is 0.10   or 0.01 ​?   Recent 78 92 90 79 58 100 62

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Listed below are time intervals​ (min) between eruptions of a geyser. Assume that the​ "recent" times are within the past few​ years, the​ "past" times are from around 20 years​ ago, and that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal. Does it appear that the mean time interval has​ changed? Is the conclusion affected by whether the significance level is

0.10
 

or

0.01
​?
 
Recent
78
92
90
79
58
100
62
88
70
89
81
82
56
80
75
102
61
 
Past
90
89
93
94
64
84
84
92
88
91
90
91
 
 
 
 
 
 
 
 
 
Let
mu
1

be the recent times and let

mu
2
be the past times. What are the null and alternative​ hypotheses?
 
 
A.
H0​:
mu

1not equalsmu

2
H1​:
mu

1equalsmu

2
 
B.
H0​:
mu

1equalsmu

2
H1​:
mu

1not equalsmu

2
 
C.
H0​:
mu

1less thanmu

2
H1​:
mu

1equalsmu

2
 
D.
H0​:
mu

1equalsmu

2
H1​:
mu

1greater thanmu

2
Calculate the test statistic.
 
tequals

enter your response here

 
​(Round to two decimal places as​ needed.)
Find the​ P-value.
 
​P-valueequals

enter your response here

 
​(Round to three decimal places as​ needed.)
Make a conclusion about the null hypothesis and a final conclusion that addresses the original claim. Use a significance level of
0.10
.
 
 
Reject
Fail to reject
H0
because the​ P-value is
 
greater than
less than or equal to
the significance level. There
 
is
is not
sufficient evidence that the mean time interval has changed.
Is the conclusion affected by whether the significance level is
0.10
 

or

0.01
​?
 
 
A.
​Yes, the conclusion is affected by the significance level because
H0
is rejected when the significance level is
0.01
 

but is not rejected when the significance level is

0.10
.
 
B.
​No, the conclusion is not affected by the significance level because
H0
is rejected regardless of whether a significance level of
0.10
 

or

0.01
 
is used.
 
C.
​Yes, the conclusion is affected by the significance level because
H0
is rejected when the significance level is
0.10
 

but is not rejected when the significance level is

0.01
.
 
D.
​No, the conclusion is not affected by the significance level because
H0
is not rejected regardless of whether a significance level of
0.10
 

or

0.01
 
is used.
 
 
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