Evaluate the expression below when x=-1. 2x^2-5/x+9
1 answer:
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Answer: No , at 0.05 level of significance , we have sufficient evidence to reject the claim that LTCC Intermediate Algebra students get less than seven hours of sleep per night, on average.
Step-by-step explanation:
Let denotes the average hours of sleep per night.
As per given , we have
, since is left-tailed and population standard deviation is unknown, so the test is a left-tailed t -test.
Also , it is given that ,
Sample size : n= 22
Sample mean :
Sample standard deviation : s= 1.93
Test statistic :
i.e.
For significance level and degree of freedom 21 (df=n-1),
Critical t-value for left-tailed test=
Decision : Since the test statistic value (0.58) > critical value 1.7207, it means we are failed to reject the null hypothesis .
[Note : When , then we accept the null hypothesis.]
Conclusion: We have sufficient evidence to reject the claim that LTCC Intermediate Algebra students get less than seven hours of sleep per night, on average.