# Thread: Need a solution to this problem

1. Originally Posted by Airjunkie
No, I dont have the information, and my school is closed all week and i want to get this done before the weekend.

So, i remember my teacher setting up my calculator or showing me how to get it into help mode, so that like, for example, if i did normalcdf it would have showed me what i needed to enter.

If i can find how to activate that help guidance thing again i will be in good shape.
Manuals for many calculators such as from the TI and Casio range can be found on-line.

2. InvNorm(Area to the left of the value you have,μ,σ)

Okay so now for q3 would i do

Invnorm(.00000001,30,sqrt of 500) ?

3. Originally Posted by Airjunkie
InvNorm(Area to the left of the value you have,μ,σ)

Okay so now for q3 would i do

Invnorm(.00000001,30,sqrt of 500) ?
I have told you that Pr(U > T) = 0.01. So the area to the left is 1 - 0.01. THis is not equal to the number in red (a number from where it has come from I have no idea).

4. Invnorm(.99,30,sqrt of 500) ?

=82.0187

not sure how that number relates to q3 though...

5. Originally Posted by Airjunkie
Invnorm(.99,30,sqrt of 500) ?

=82.0187

not sure how that number relates to q3 though...
T = 82.0187 and I have previously defined what T. Read the guidance that has previously been posted. Please.

6. Thanks again.

2.)91% of the days the train will have to wait

3.) They should delay the train 82.01 minutes so that the probability to wait is .01.

I beleive we've finally made it through this problem eh?

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