For questions 1&2 below, label and define the parameters and statistics it gives you: Example: How much do prices vary for filling a cavity? To find out, an insurance company conducted a survey of 10 randomly
selected dental practices. The average cost to fill a cavity was $340 with a standard deviation of $42.
The sample is the 10 prices reported by the 10 dental practices.
The population is all of the cavity filling prices in California.
xbar = 340, the average cost to fill a cavity in our sample.
s = 42, the standard deviation in our sample of the cost to fill a cavity.
1. On Tuesday, the bottles of Arizona Iced Tea filled in a plant were supposed to contain an average of 20 ounces of iced tea.
Quality control inspectors selected 50 bottles at random from the day's production. These bottles contained an average of 19.6
ounces of iced tea.
The sample is...
The population is...
xbar =
2. From a large group of 25,000 people who signed a card saying they intended to quit smoking, 1000 people were selected at
random. It turned out that 210 of these individuals had not smoked over the past 6 months.
The population is...
The sample is...
p-hat =
3. A study of the health of teenagers plans to measure the bloos cholesterol levels of a random sample of 13-16 year olds. The
researchers will report the mean x-bar from their sample as an estimate of the mean cholesterol level mu in this population.
Explain to someone who knows little about statistics what x bar is, how it helps find mu, and what mu is.