How Many Apps for Your Smartphone?

A random sample ofn

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461

smartphone users in the US in January 2015 found that 355 of them have downloaded an app.¹Of then

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355

smartphone users who had downloaded an app, the average number of apps downloaded was 19.7.

¹Olmstead K and Atkinson M, "Apps Permissions in the Google Play Store,"pewresearch.org, November 10, 2015.

(a) Give notation for the parameter of interest.

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(b) Give the notation for the quantity we use to make the estimate.

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(c) Give the value of the best estimate.

Enter the exact answer.

Best estimate =

Enter your answer in accordance to the question statement