AP Statistics Hypothesis Test for Proportions

Margin of error equals:

• Critical Value ∗ standard Error

• z*

• 1.96

• Standard Error

When conducting a significance test for the difference in proportions, why do we pool the data when finding standard error?

• Because we like to swim

• Because we assume p1 = p2 in Ho

• Because the sample sizes are always equal

• To be safe and make sure we don't underestimate the standard error

• Because we don't the standard deviation.

A leading research firm reports that 33% of young adults have completed a college degree.  One state leader who is trying to create more scholarship money for college believes that the rate is lower than that in his state.  The state leader commissions a study that surveys 500 young adults in the same age bracket as the national study to see if they have completed a college degree.  Of the 500 interviewed, 152 have completed a college degree.  Conduct a hypothesis test to see if the state leader has evidence to support his claim.

• 0.05

• α

• 0.330

• x

• 500

• p

• 152

• p̂

• 0.304

• n

In one year, a national vital statistics report indicated that about 3% of all births produced twins.  Data from a large city hospital found only 7 sets of twins were born to 469 teenage girls.  Does that suggest that mothers under age 20 may be less likely to have twins?  Test at a .05 significance level.

Identify the hypothesis statement:

H₀ : ​ (a)  

H_a : ​ (b)  

• p = 0.03

• p < 0.03

• µ= 0.03

• μ< 0.03

• p0=0.03

• p0<0.03

• p>0.03

• p = 0.05

• μ = 0.05

The manufacturer of soft drink A advertises that they have 60% of the soft drink market. A consumer group that monitors sales thinks that this percentage is no longer true. In a blind taste test of 100 people, 58 people selected soft drink A.  Is this evidence that the percentage of the market for soft drink A is different than advertised? Match the following

• 0.58

• n

• 58

• p

• 100

• p̂

• 0.05

• α

• 0.6

• x

The manufacturer of soft drink A advertises that they have 60% of the soft drink market. A consumer group that monitors sales thinks that this percentage is no longer true. In a blind taste test of 100 people, 58 people selected soft drink A. Is this evidence that the percentage of the market for soft drink A is different than advertised?

• p = 0.6

• p ≠ 0.6

• p0 = 0.6

• p0 < 0.6

• p>0.6

• p = 0.58

• p≠0.58

• p0 = 0.58

• p0 ≠ 0.58

In one year, a national vital statistics report indicated that about 3% of all births produced twins.  Data from a large city hospital found only 7 sets of twins were born to 469 teenage girls.  Does that suggest that mothers under age 20 may be less likely to have twins?  Test at a .05 significance level.

• 7

• x

• 3%

• p̂

• 469

• n

• 5%

• p₀

• 1.5%

• α

Many television viewers express doubts about the validity of certain commercials. In an attempt to answer their critics, Timex Group USA wishes to estimate the proportion of consumers who believe what is shown in Timex television commercials. Let p represent the true proportion of consumers who believe what is shown in Timex television commercials. What is the smallest number of consumers that Timex can survey to guarantee a margin of error of 0.05 or less at a 99% confident level?

• 550

• 600

• 650

• 700

• 750

What interval should be used?

• 2 Proportion z interval

• 1 Proportion t interval

• 1 Proportion z interval

• Chi Square for Goodness of Fit

What is the expected count of a female who likes Pepsi?

• 10.5

• 11

• 14.5

• 6.3