Ch 1: Collecting Data

The city of Raleigh has 10600 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 300 randomly selected registered voters was conducted. 105 said they'd vote for Brown, 172 said they'd vote for Feliz, and 23 were undecided.Give the sample statistic for the proportion of voters surveyed who said they'd vote for Brown. Note: The proportion should be a fraction or decimal, not a percent.

105/300=0.35 0.35*10600=3,710

The city of Raleigh has 10700 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 350 randomly selected registered voters was conducted. 161 said they'd vote for Brown, 182 said they'd vote for Feliz, and 7 were undecided.Give the sample statistic for the proportion of voters surveyed who said they'd vote for Brown. Note: The proportion should be a fraction or decimal, not a percent.

161/350=0.46 0.46*10700=4,922

The city of Raleigh has 8900 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 550 randomly selected registered voters was conducted. 265 said they'd vote for Brown, 230 said they'd vote for Feliz, and 55 were undecided. Give the sample statistic for the proportion of voters surveyed who said they'd vote for Brown. Note: The proportion should be a decimal rounded to 3 decimal places. _______________________ This sample statistic suggests that we might expect _________ of the 8900 registered

265/550=.482 .482*8900=4,289.80

A political scientist surveys 38 of the current 88 representatives in a state's legislature. What is the size of the sample: What is the size of the population:

38/88

The city of Raleigh has 10400 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 600 randomly selected registered voters was conducted. 326 said they'd vote for Brown, 214 said they'd vote for Feliz, and 60 were undecided. Describe the population the surveyors are really interested in.

All registered voters in Raleigh

The city of Raleigh has 8600 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 250 randomly selected registered voters was conducted. 86 said they'd vote for Brown, 150 said they'd vote for Feliz, and 14 were undecided. Describe the target population for this survey.

All registered voters in Raleigh

The city of Raleigh has 10300 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 550 randomly selected registered voters was conducted. 241 said they'd vote for Brown, 258 said they'd vote for Feliz, and 51 were undecided. Describe the population ACTUALLY represented by this survey.

All registered voters with telephones in Raleigh

You want to estimate how many fish there are in a pond. Suppose you capture 280 fish, tag them, and throw them back into the pond. After a couple of days, you go back to the pond and capture 560 fish, of which 28 are tagged. An estimate for the number of fish in the pond is ____________ fish

Data obtained from the question Tagged fish in pond = 280 - 140 Captured fish = 560 - 420 Captured tagged fish = 28 Total fish = y =? The estimated fish in pond can be obtained as follow: Tagged in pond / Total in pond = captured tagged fish / Captured fish 280 / y = 28 / 560 Cross multiply y × 28 = 280 × 560 y × 28 = 156,800 Divide both side by 28 y = 58800 / 28 y = 5600 Thus, the estimated fish in the pond is 5600

The city of Raleigh has 8000 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 350 randomly selected registered voters was conducted. 126 said they'd vote for Brown, 195 said they'd vote for Feliz, and 29 were undecided.Describe the sampling frame for this survey.

FIND ANSWER FOR THIS QUESTION: All citizens of Raleigh All registered voters in Raleigh All registered voters with telephones in Raleigh The 350 voters surveyed The 126 voters who said they'd vote for Brown None of the above

The city of Raleigh has 9400 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 350 randomly selected registered voters was conducted. 140 said they'd vote for Brown, 177 said they'd vote for Feliz, and 33 were undecided. Describe the sample for this survey.

The 350 voters surveyed

The city of Raleigh has 10200 registered voters. There are two candidates for city council in an upcoming election: Brown and Feliz. The day before the election, a telephone poll of 600 randomly selected registered voters was conducted. 273 said they'd vote for Brown, 273 said they'd vote for Feliz, and 54 were undecided. Describe the sample for this survey.

The 600 voters surveyed

A researcher interested in Springfield citizens' shopping habits surveys a randomly selected group of 200 Walmart shoppers. 76% of those surveyed indicated that price was more important to them than where an item was produced. The researcher concluded that "about three-quarters of the people in Springfield are more concerned with cost than where an item is made. This conclusion might be invalid because:

the sample is not representative of the population.