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How to find this statistics question?

How do you do part 2 of this question, I just don't understand it?
p.s answer is 775, 757, 577
stats q june 2013.docx200.5KB
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Avatar for shamika
shamika
16
Original post by underestimate
How do you do part 2 of this question, I just don't understand it?
p.s answer is 775, 757, 577


You are trying to make 19 from a sum of three numbers. Those numbers can be 1, 3, 5, or 7, and repeats are allowed (this should be obvious because if they weren't, the largest you number you would be able to make is 3 + 5 + 7 = 15).

What possible combinations do you have?
Original post by shamika
You are trying to make 19 from a sum of three numbers. Those numbers can be 1, 3, 5, or 7, and repeats are allowed (this should be obvious because if they weren't, the largest you number you would be able to make is 3 + 5 + 7 = 15).

What possible combinations do you have?



Thanks I have the numbers 1,3,5,7, does this then form a number like 775, I just don't get why it would form a number, instead of separate values.
Reply 3
Avatar for shamika
shamika
16
Original post by underestimate
Thanks I have the numbers 1,3,5,7, does this then form a number like 775, I just don't get why it would form a number, instead of separate values.


I'm not sure I understand your question. X1+X2+X3X_1 + X_2 + X_3 is a random variable, but when you assign a value to it, in this case 19, you can figure out the possible values X_1, X_2 and X_3 can take.

In this case, one possibility is X_1 = 7, X_2 = 7 and X_3 = 5, and 7+7+5=19
Original post by shamika
I'm not sure I understand your question. X1+X2+X3X_1 + X_2 + X_3 is a random variable, but when you assign a value to it, in this case 19, you can figure out the possible values X_1, X_2 and X_3 can take.

In this case, one possibility is X_1 = 7, X_2 = 7 and X_3 = 5, and 7+7+5=19


Oh I understand, I thought it formed a new number like 774.
Thanks

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