# Math Help - P-value

1. ## P-value

On a summer day it says that the probability that a hot dog stand will sell out of hot dogs is 3/5
find at least 70 of 100 days the hotdogs are sold out

I used 1-Binomcdf(100, (3/5), 70) then this gives me an answer that is not a choice.

2. Originally Posted by IDontunderstand
On a summer day it says that the probability that a hot dog stand will sell out of hot dogs is 3/5
find at least 70 of 100 days the hotdogs are sold out

I used 1-Binomcdf(100, (3/5), 70) then this gives me an answer that is not a choice.
At least means 70 or more.

X ~ Binomial(n = 100, p = 3/50 and your job is to calculate $\Pr(X \geq 70) = 1 - \Pr(X \leq {\color{red}69})$.

3. most likely you're expected to approximate this with a normal distribution with

$P(Normal >69.5)$

4. Originally Posted by matheagle
most likely you're expected to approximate this with a normal distribution with

$P(Normal >69.5)$
Not this time. The Binomcdf command mentioned in the original post suggests using a TI graphics or CAS calculator here.

5. I don't own any of these calculators, so I had no idea what that meant.
The most scientific one I use is a TI-30.
I had a fancier one that did all these percentiles, but I gave that to a grad student last year as a graduation gift.
I just googled binomial calculator and came across
Binomial Probability Calculator
These can be found all over the net.