7.4 - Test Yourself!
7.4 - Test Yourself!Think About It!
Select the answer you think is correct - then click the right arrow to proceed to the next question.
Customers at a gas station pay with a credit card, a debit card, or cash. Seventy percent don’t pay with cash, and 20% use a debit card. What is the probability that a randomly selected customer pays with cash?
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The answer is 0.3. By the rule of the opposites since 70% don’t pay with cash, the other 30% do.
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Correct. 0.3. By the rule of the opposites since 70% don’t pay with cash, the other 30% do.
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The answer is 0.3. By the rule of the opposites since 70% don’t pay with cash, the other 30% do.
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The answer is 0.3. By the rule of the opposites since 70% don’t pay with cash, the other 30% do.
Customers at a gas station pay with a credit card, a debit card, or cash. Seventy percent don’t pay with cash, and 20% use a debit card. What is the probability that a randomly selected customer pays with a credit card?
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The answer is 0.5. Since all of the ways to pay are mutually exclusive we see that 30% pay with cash, 20% pay with a debit card so the remaining 50% must pay with a credit card.
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The answer is 0.5. Since all of the ways to pay are mutually exclusive we see that 30% pay with cash, 20% pay with a debit card so the remaining 50% must pay with a credit card.
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The answer is 0.5. Since all of the ways to pay are mutually exclusive we see that 30% pay with cash, 20% pay with a debit card so the remaining 50% must pay with a credit card.
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Correct. 0.5. Since all of the ways to pay are mutually exclusive we see that 30% pay with cash, 20% pay with a debit card so the remaining 50% must pay with a credit card.
True or False: In tossing a fair coin, the probability that you get Heads on between 49% and 51% of the tosses decreases as the number of tosses increases.
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The answer is FALSE. The Law of Large Numbers says that the probability increases for getting within 1% of what you expect as the number of trials goes up.
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Correct. The Law of Large Numbers says that the probability increases for getting within 1% of what you expect as the number of trials goes up.
True or False: In spinning a roulette wheel, there is a 47% chance that the result comes up red. Thus, the chance that red comes up a majority of the time is greater with 50 spins than it is with 700 spins.
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Correct. A majority means over 50% and getting more than 3% away from what you expect is more likely with fewer trials when things are more variable.
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The answer is TRUE. A majority means over 50% and getting more than 3% away from what you expect is more likely with fewer trials when things are more variable.
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Correct. It is unlikely that the method of payment for one customer affects the method used by another customer. However, if one customer is wearing a coat then it is more likely that the next customer is also wearing a coat (since it’s probably cold outside).
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It is unlikely that the method of payment for one customer affects the method used by another customer. However, if one customer is wearing a coat then it is more likely that the next customer is also wearing a coat (since it’s probably cold outside).
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Correct. $2.61. The expected value is found as the weighted average (summing amounts times probabilities).
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The answer is $2.61. The expected value is found as the weighted average (summing amounts times probabilities).
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The answer is $2.61. The expected value is found as the weighted average (summing amounts times probabilities).
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