Download One-Sample z Interval Homework

One-Sample z Interval Homework
1. The gas mileage for a certain model of car is known to have a standard deviation of 5 mpg. A simple
random sample of 64 cars of this model is chosen and found to have a mean gas mileage of 27.5
mpg. Construct and interpret a 95% confidence interval for the mean gas mileage for all cars of this
model.
P: Identify the population of interest and the parameter you want to estimate.
A: Verify the assumptions/conditions.
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Random.

Normal.

Independent.
N: Name the appropriate inference procedure.
I: Carry out the inference procedure. Carry out the interval.
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C: State your conclusion in the context of the problem.
2. The mean height of a random sample of 70 Washburn students is 65 inches. Suppose the standard
deviation of all Washburn student heights is 3 inches. Construct and interpret a 90% confidence
interval for the mean height of all Washburn students.