Answer:
Step-by-step explanation:
Given that a professor sets a standard examination at the end of each semester for all sections of a course. The variance of the scores on this test is typically very close to 300.
(Two tailed test for variance )
Sample variance =480
We can use chi square test for testing of hypothesis
Test statistic =
p value = 0.0100
Since p <0.05 our significance level, we reject H0.
The sample variance cannot be claimed as equal to 300.
Answer:
So it would takes approximately 6.9 hours to reach 32 F.
Step-by-step explanation:
For this case we have the following differential equationÑ
We can reorder the expression like this:
We can use the substitution and
so then we have:
IF we integrate both sides we got:
If we apply exponential in both sides we got:
And if we replace w = u-T we got:
We can also express the solution in the following terms:
For this case we know that since w ehave a cooloing,
, we have this model:
And if we want that the temperature would be 32F we can solve for t like this:
If we apply natural logs on both sides we got:
So it would takes approximately 6.9 hours to reach 32 F.