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1. If a student's course grade was a B, what is the probability that a randomly selected student did at least 30 minutes of homework at night?

2. Are the events "did at least 30 minutes of homework l" and "course grade is a B" independent? Explain your answer.​

1 If a students course grade was a B what is the probability that a randomly selected student did at least 30 minutes of homework at night 2 Are the events did class=

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sqdancefan

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Answer:

  1. 0.70
  2. yes

Step-by-step explanation:

1. P(≥30 | B) = P(≥30 & B)/P(B)

  P(≥30 | B) = 0.21/0.30 = 0.70

The probability that a B student did at least 30 minutes of homework is 0.70.

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2. The probability that any student did at least 30 minutes of homework is shown in the column a the right end of the table: 0.70. This is the same as the probability that a B student did at least 30 minutes of homework. That is ...

  P(≥30 | B) = P(≥30)

Hence, the events "at least 30 minutes of homework" and "B student" are independent.

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