$\"\"$

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(a)

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Americas chew an average of $\"\"$ sticks of gum per year.

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Therefore, $\"\"$ .

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Standard deviation is $\"\"$ sticks.

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Find the probability that $\"\"$ people chew an average of $\"\"$ sticks or more per year.

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Here $\"\"$ .

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Find $\"\"$ .

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Standard deviation of a sample mean is $\"\"$ .

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Substitute $\"\"$ and $\"\"$ in the formula.

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$\"\"$

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$\"\"$ .

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Use the $\"\"$ -value formula for a sample mean to find the $\"\"$ -value for $\"\"$ .

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$\"\"$ -value formula: $\"\"$ .

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Substitute $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Find the probability.

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$\"\"$

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Using $\"\"$ score table:

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The area for $\"\"$ is $\"\"$ .

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$\"\"$

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$\"\"$ .

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Probability that $\"\"$ people chew an average of $\"\"$ sticks or more per year is $\"\"$ .

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$\"\"$

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(b)

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Sample size is $\"\"$ .

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Find the probability that an average number of sticks is between $\"\"$ and $\"\"$ per year.

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Find $\"\"$ .

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Standard deviation of a sample mean is $\"\"$ .

\

Substitute $\"\"$ and $\"\"$ in the formula.

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$\"\"$

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$\"\"$ .

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Use the $\"\"$ -value formula for a sample mean to find the $\"\"$ -value for $\"\"$ and $\"\"$ .

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Find $\"\"$ -value for $\"\"$ .

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$\"\"$ -value formula: $\"\"$ .

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Substitute $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Using $\"\"$ -score calculator:

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The area for $\"\"$ is $\"\"$ .

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Find $\"\"$ -value for $\"\"$ .

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$\"\"$ -value formula: $\"\"$ .

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Substitute $\"\"$ , $\"\"$ and $\"\"$ .

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$\"\"$

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$\"\"$ .

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Using $\"\"$ score calculator:

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The area for $\"\"$ is $\"\"$ .

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Find the probability.

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$\"\"$

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$\"\"$ \ \

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$\"\"$

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$\"\"$ . \ \

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Probability that an average number of sticks is between $\"\"$ and $\"\"$ per year is $\"\"$ .

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$\"\"$

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(a) Probability that $\"\"$ people chew an average of $\"\"$ sticks or more per year is $\"\"$ .

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(b) Probability that an average number of sticks is between $\"\"$ and $\"\"$ per year is $\"\"$ . \ \