Answer:
Step-by-step explanation:
Given that an automatic machine is set to fill bags of dog food with exactly 25 pounds on average with a standard deviation of 0.5 pounds.
Sample size = n =100
x bar = 24.85 pounds
Sample std error =
Hypotheses:
(Two tailed test at 5% level)
Mean difference =0.15
Test statistic = mean diff/se = 3
Since population std dev is known z test can be used
p value =0.0000
Since p <0.05 we find that the bag does not contain exactly 25 pounds.
Answer:
The 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the average using the finite correction factor is:
The information provided is:
The critical value of <em>z</em> for 95% confidence level is,
<em>z</em> = 1.96
Compute the 95% confidence interval for the average number of years until the first major repair as follows:
Thus, the 95% confidence interval for the average number of years until the first major repair is (3.1, 3.5).