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3 years ago

For two independent events A and B, Pr(A or B) = 0.8 and Pr(B) = 0.3. From this, find Pr(A).

Mathematics

1 answer:

balu736 [363]3 years ago

7 0

Answer:

please give me brainlist and follow

Step-by-step explanation:

Correct option is

5/7

As A and B are independent

0.8=P(A∪B)=P(A)+P(B)−P(A)P(B)

=0.3+P(B)−(0.3)P(B)

⇒0.5=(0.7)P(B)⇒7P(B)=5

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An Article a Florida newspaper reported on the topics that teenagers most want to discuss with their parents. The findings, the

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Answer:

The estimate is $P__{hat}} \pm E = 0.37 \pm 0.0348$

Step-by-step explanation:

From the question we are told that

The sample size is n = 522

The sample proportion of students would like to talk about school is $\r p__{hat}} = 0.37$

Given that the confidence level is 90 % then the level of significance can be mathematically evaluated as

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Next we obtain the critical value of $\frac{\alpha }{2}$ from the normal distribution table, the value is

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Generally the margin of error can be mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \sqrt{\frac{\r P_{hat}(1- \r P_{hat} )}{n } }$

=> $E = 1.645 * \sqrt{\frac{0.37 (1- 0.37 )}{522 } }$

=> $E = 0.0348$

Generally the estimate the proportion of all teenagers who want more family discussions about school at 90% confidence level is

$P__{hat}} \pm E$

substituting values

$0.37 \pm 0.0348$

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