Sample Z Test Means

White blood cell counts are normally distributed with mean 7500 and variance 500. If a patient has taken 50 laboratory blood tests that have a mean of 6899.75 and a standard deviation of 393.44, does this give evidence that his white blood cell count is significantly different than normal?

• One-Sample T Test for a Mean

• One-Sample Z Test for a Proportion

• One-Sample Z Test for a Mean

• One-Sample T Test for a Proportion

A leading auto manufacturer claimed that a popular version of its minivan was available in the Midwest foran average price or $16,000 with a standard deviation of $800. A consumer group doubted that report andsurveyed 50 recent purchasers of the minivan to dispute the manufacturer's claim. They came up with anaverage of $16,277. Does this show that the manufacturer is making a false claim?

• One-Sample Z Test for a Mean

• Matched-Pairs T Test for a Mean

• Two-Sample T Test for the Difference in Means

• One-Sample Z Test for a Proportion

USA Today reported that in 1992, 39% of all elementary school children claimed that when they grow up they want to do something to help other people. However, in 1995, 128 of a random sample of 317 of these same children claimed that when they grow up they want to do something to help other people. Does this information indicate that there has been an attitude change either way?

• One-Sample Z Test for a Proportion

• Two-Sample Z Test for the Difference in Proportions

• One-Sample T Test for a Mean

• Two-Sample T Test for the Difference in Means

The manufacturer of a particular brand of microwave popcorn claims that only 2 percent of its kernels of corn fail to pop. A competitor, believing that the actual percentage is larger, tests 2,000 kernels and finds that 44 failed to pop. Do these results provide sufficient evidence to support the competitor's belief?

• One-Sample Z Test for a Proportion

• One-Sample T Test for a Mean

• Two-Sample Z Test for a Proportion

• Matched-Pairs T Test for a Mean

A recruiter for the Super Teachers School Board advertised that the average teacher's salary in a certain competing district is less than what his district offers, $50,000. A random sample of 50 teachers from the competing district had a mean annual salary of $48,300. The population standard deviation is known to be $8,000. Use a 0.01 level of significance to test the recruiter's claim.

What type of test should you run?

• Z test

• T test

• 1-Prop Z test

• X² test

A recruiter for the Super Teachers School Board advertised that the average teacher's salary in a certain competing district is less than what his district offers, $50,000. A random sample of 50 teachers from the competing district had a mean annual salary of $48,300. The population standard deviation is known to be $8,000. Use a 0.01 level of significance to test the recruiter's claim. What type of test should you run?

• Z test

• T test

• 1-Prop Z test

• X² test

• A

• B

• C

• D

• E

A recruiter for the Super Teachers School Board advertised that the average teacher's salary in a certain competing district is less than what his district offers, $50,000. A random sample of 50 teachers from the competing district had a mean annual salary of $48,300. The population standard deviation is known to be $8,000. Use a 0.01 level of significance to test the recruiter's claim.

What is your decision?

• Reject the Null

• Fail to Reject the Null

• Accept the Null

If you wish to test the claim that the mean of the population is 100, the appropriate alternate hypothesis is

Thirty randomly selected students took the calculus final. If the sample mean was 92 and the standard deviation was 9.4, construct a 99 percent confidence interval for the mean score of all students from which the sample was gathered.

• 89.08 < μ < 94.92

• 87.27 < μ < 96.73

• 87.29 < μ < 96.71

• 87.77 < μ < 96.23