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Chapter 10: Q.2.1 (page 611)

Are teens or adults more likely to go online daily? The Pew Internet and American Life Project asked a random sample of 800 teens and a separate random sample of 2253 adults how often they use the Internet. In these two surveys, 63% of teens and 68%of adults said that they go online every day. Construct and interpret a 90% confidence interval for p1-p2?

Short Answer

Expert verified

The mean and standard deviations are 10 and 0.205 respectively.

Step by step solution

01

Given Information

Sample mean x炉1=27.

Sample mean x炉2=17.

Standard deviation 蟽1=0.8.

Standard deviation 蟽2=0.5.

02

Explanation

The formulas to compute the mean and standard deviation are:

渭1-2=渭1-渭2

蟽1-2=蟽12+n1蟽22n2

The mean and standard deviation could be computed as:

渭1-2=渭1-渭2

=27-17

=10

蟽1-2=蟽12+n1蟽22n2

=0.8225+0.5220

=0.205

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Most popular questions from this chapter

Down the toilet A company that makes hotel toilets claims that its new pressure-assisted toilet reduces the average amount of water used by more than 0.5a gallon per flush when compared to its current model. To test this claim, the company randomly selects 30toilets of each type and measures the amount of water that is used when each toilet is flushed once. For the current-model toilets, the mean amount of water used is1.64a gal with a standard deviation of 0.29gal. For the new toilets, the mean amount of water used is 1.09galwith a standard deviation of 0.18gal.

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(b) localid="1650367573248" 0.03卤1.96(0.28)(0.72)125+(0.25)(0.75)68

(c) 0.03卤1.645(0.28)(0.72)125+(0.25)(0.75)68

(d)

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