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9.025 Mean and standard deviation of sample proportions

Interactive practice questions

In Italy, $37%$37% of Italians also speak English. If a sample of $200$200 Italians in Italy are selected at random, determine:

a

The expected number in the sample who speak English.

b

The expected sample proportion of English speakers.

c

The standard deviation of the sample proportions of English speakers.

Round your answer to three decimal places.

Medium
2min

$15%$15% of all customers at a book store bought at least one autobiography. In a random sample of $100$100 customers, determine:

Medium
2min

On any day of the year, approximately $42000$42000 of the $400000$400000 people residing in the city of Florence are tourists. Determine, in a random sample of $600$600 people:

Medium
2min

A social media advertising campaign gets an average of $150$150 follows per $1000$1000 users who see the advertisement.

Medium
3min
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Outcomes

ACMMM174

understand the concept of the sample proportion ˆp as a random variable whose value varies between samples, and the formulas for the mean p and standard deviation √(p(1−p)/n of the sample proportion ˆp

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