A message center receives calls from 6 p.m. until 6 a.m. Typically, 50% of the calls come in between 6 p.m. and 9 p.m.; 25% of the calls come in between 9 p.m. and midnight; 20% of the calls come in between midnight and 3 a.m.; and 5% of the calls come in between 3 a.m. and 6 a.m.

What is the probability that a call will come in between 6 p.m. and midnight?
@directrix

Question

A message center receives calls from 6 p.m. until 6 a.m. Typically, 50% of the calls come in between 6 p.m. and 9 p.m.; 25% of the calls come in between 9 p.m. and midnight; 20% of the calls come in between midnight and 3 a.m.; and 5% of the calls come in between 3 a.m. and 6 a.m.

What is the probability that a call will come in between 6 p.m. and midnight?
@directrix

anonymous · Answer

Do you have options?

daniellelovee · Answer

is it 75 because 25+50 and no I don't sorry

anonymous · Answer

Yes it is a 75% probability

daniellelovee · Answer

@Directrix do you agree?

directrix · Answer

I have been reading about RANDOM VARIABLES AND DISTRIBUTION.

Supposedly, adding the individual probabilities is the way to go.

So that would be 50% from 6 to 9 and 25% from 9 to 12 which would give 75% probability or .75 for the 6 to 12 call center load of calls.

directrix · Answer

Here's where I was reading if anyone is interested: http://k12.kitaboo.com/k12/ebookpdf/maths05/17501_HS_PS_chapter04.pdf

daniellelovee · Answer

so my work was right then?

directrix · Answer

@amistre64   Any comments or suggestions on this problem?

amistre64 · Answer

the probability distribution is already defined, so its the sum of the 'area' under the curve ...
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