Using probabilities concepts, it is found that:
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A probability is the number of desired outcomes divided by the number of total outcomes.
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Item a:
[tex]p = \frac{234}{467} = 0.5011[/tex]
0.5011 = 50.11% probability that the customer is at least 20 but no older than 49.
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Item b:
[tex]p = \frac{309}{467} = 0.6617[/tex]
0.6617 = 66.17% probability that the customer is either older than 40 or younger than 20.
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Item c:
[tex]p = \frac{151}{467} = 0.3233[/tex]
0.3233 = 32.33% probability that the customer is at least 50.
A similar problem is given at https://brainly.com/question/15536019