Answer:
For x∈ {-∞,-3} y<0, below x-axis
x∈ {-3,-1} y>0, above x-axis
x∈ {-1,4} y<0, below x-axis
x∈ {4,∞} y>0, above x-axis
Step-by-step explanation:
f(x)=
=0
For x∈ {-∞,-3} y<0, below x-axis
x∈ {-3,-1} y>0, above x-axis
x∈ {-1,4} y<0, below x-axis
x∈ {4,∞} y>0, above x-axis
Answer:
We accept the null hypothesis and the population mean is $120.
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 100
Sample mean, = $120
Alpha, α = 0.01
Sample standard deviation, s = $25
First, we design the null and the alternate hypothesis
We use two-tailed t test to perform this hypothesis.
Formula:
Putting all the values, we have
p-value one tail= 0.024
p-value two tail= 0.048
Conclusion:
Since the p-value for two tailed test is greater than the significance level, we fail to reject the null hypothesis and accept it.
Thus, the population mean is $120.