Transcript Notes on Using the Calculator for 1 sample tests & intervals

One sample Tests &
Intervals on the
Calculator
The ages of a group of volunteers were: 27, 16, 9, 14, 32, 15, 16,
13. The manager wants to show that the average age is less than
the national average of 18. Test at a 5% significance level.
Give the hypotheses:
Put your data in L1
What kind of Test? (Use formula)
Output
Go to Stat → Test
Result:
Input
A researcher claims that the average wind speed in a certain city
is 8 mph. A sample of 32 days has an average wind speed of 8.2
mph and the standard deviation is 6mph. At 10% significance, is
there enough evidence to reject the claim.
Give the hypotheses:
Go to Stat → Test
What kind of Test? (Use formula)
Output
Result:
Input
The average weight of 60 randomly selected compact automobiles
was 2627 pounds. The standard deviation was $33. Find the 90%
confidence interval of the population mean.
What kind of Interval? (Use formula)
Go to Stat → Test
Output
Input
Result:
Find the mean of the given
interval.
Educators estimate the dropout rate is 15%. Last year 38
seniors from a random sample of 200 seniors withdrew. At
a 5% significance level, is there enough evidence to reject
the claim?
Hypotheses:
What kind of Test? (Use formula)
Go to Stat → Calc → Test
Output
Input
Result:
In a study of 204 accidents that required treatment in an
emergency room, 42% occurred at home. Find the 95%
confidence interval of the true proportion of accidents that
occur at home.
What kind of Interval? (Use formula)
Go to Stat → Calc → Test
Output
Input
Result:
A telephone company representative estimates that 40% of its
customers want call-waiting. To test this hypothesis, she
selected a sample of 105 customers and found that 37% had call
waiting. At a 1% significance, is her estimate appropriate?
Hypotheses:
What kind of Test? (Use formula)
Go to Stat → Calc → Test
Output
Input
Result:
Homework
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Worksheet
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Identify the hypothesis
Give the formula
Give the test statistic
Give the p-value
State the decision