Hypothesis Testing 7.1

A mayor is concerned about the percentage of city residents who express disapproval of his job performance.  His political committee pays for a newspaper ad, hoping to keep his disapproval rating below 21%.  They will use a follow up poll to access effectiveness.  What are the correct null and alternative hypotheses?

• Ho: p=.21
  Ha: p > .21
• Ho: p< .21
  Ha: p= .21
• Ho: p> .21
  Ha: p= .21
• Ho: p= .21
  Ha: p< .21

5% of trucks of a certain model have needed new engines after being driven between 0 and 100 miles.  The manufacturer hopes that the redesign of one of the engine's components has solved this problem.  Write the null and alternative hypotheses for this situation.

• Ho:  p< 0.05
  Ha:  p = 0.05
• Ho:  p = 0.05
  Ha:  p > 0.05
• Ho:  p = 0.05
  Ha:  p < 0.05
• Ho:  p > 0.05
  Ha:  p = 0.05

A P-value indicates:

• the probability that the null hypothesis is true
• the probability that the alternative hypothesis is true
• the probability of the observed statistic given the null hypothesis is true
• the probability that the null is true given the observed statistic

Proposes what we should conclude if we find the null hypothesis to be unlikely

• Null Hypothesis
• Alternative Hypothesis
• Assumptions & Conditions
• P-Hat

The probability of observing a value for a test statistic at least as far from the hypothesized value as the statistic value actually observed if the null hypothesis is true

• P-Hat
• One-Proportion z-test
• Z*
• P-Value

Which of the following is the FIRST step of a hypothesis test?

• Check assumptions & conditions
• Find your test statistic
• State your conclusion
• State your null & alternative hypotheses

Which of the following represents the appropriate null & alternative hypotheses?
The mean height of women is greater than 64"

• H₀: μ > 64"
  Hₐ: μ ≠ 64"
• H₀: μ = 64"
  Hₐ: μ > 64"
• H₀: p > 64"
  Hₐ: p ≠ 64"
• H₀: p = 64"
  Hₐ: p > 64"

A type I error is when:

• null hypothesis is rejected when it is true

• null hypothesis is retained when it is false

A Type I error is when: 

• We obtain the wrong test statistic
• We reject the null hypothesis when it is actually true
• We fail to reject the null hypothesis when it's actually false
• We reject the alternate hypothesis when it's actually true

What is the only option for the null hypothesis? 

• H₀ = k
• H₀ > k
• H₀ < k
• H₀ ≠ k