I'll help but information is missing, you need to have the cost and the number of pencil she will buy
Conditional probability is a measure of the probability of an event given that another event has occurred. If the event of interest is A and the event B is known or assumed to have occurred, "the conditional probability of A given B", or "the probability of A under the condition B", is usually written as P(A|B), or sometimes

.
The conditional probability of event A happening, given that event B has happened, written as P(A|B) is given by

In the question, we were told that there are three randomly selected coins which can be a nickel, a dime or a quarter.
The probability of selecting one coin is

Part A:
To find <span>the probability that all three coins are quarters if the first two envelopes Jeanne opens each contain a quarter, let the event that all three coins are quarters be A and the event that the first two envelopes Jeanne opens each contain a quarter be B.
P(A) means that the first envelope contains a quarter AND the second envelope contains a quarter AND the third envelope contains a quarter.
Thus

</span><span>P(B) means that the first envelope contains a quarter AND the
second envelope contains a quarter
</span><span>Thus

Therefore,

Part B:
</span>To find the probability that all three coins are different if the first envelope Jeanne opens contains a dime<span>, let the event that all three coins are different be C and the event that the first envelope Jeanne opens contains a dime be D.
</span><span>

</span><span>

</span><span>
Therefore,

</span>
Let x be unknown number. If number x is multiplied by
and the product is equal to
then

To find x you should divide
by

Answer: 
Answer:
The correct answer is Option A.) The standard deviation of the distribution of sample means is less than the population standard deviation of the number of cancer spots.
Step-by-step explanation:
The standard deviation of the distribution of sample means is less than the population standard deviation of the number of cancer spots.
0.25 inches represents 1 mile
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Find 1 inch:
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1 inch represents 1 ÷ 0.25 miles
1 inch represents 4 miles
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Find 3.75 inches:
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1 inch represents 4 miles
3.75 inches represent 4 x 3.75 miles
3.75 inches represent 15 miles
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Find 2.25 inches:
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1 inch represents 4 miles
2.25 inches represent 4 x 2.25 miles
2.25 inches represent 9 miles
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Find Area:
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Area = Length x Width
Area = 15 x 9
Area = 135 miles²
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Answer: 135 miles²
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