Wednesday

July 30, 2014

July 30, 2014

Posted by **Shannon** on Sunday, December 5, 2010 at 10:02am.

Grade Frequency

A 2

B 8

C 11

D 2

F 1

I think it is 1 out of 5 or 4 but I am not sure? Please help :) Thank you much!

- Math -
**MathMate**, Sunday, December 5, 2010 at 10:04amThere are 5 possible outcomes, one of which is a B.

So what is P(B), and what is P(not B)?

Hint : P(B) and P(not B) have to add up to 1.

- Math -
**Shannon**, Sunday, December 5, 2010 at 10:10amOh ok I think I get it, so P(B)=0.5, 1/2,

and P(not B)=0.5,1/2???

Is that right?

- Math -
**MathMate**, Sunday, December 5, 2010 at 11:13amSorry, not really.

Figure out the probability of P(B) which is to get B out of 5 possible choices.

The rest would be easy to figure out.

- Math -
**Jen**, Sunday, December 5, 2010 at 1:20pmAdd up all the grades that aren't B's. Then put that over the total amount of grades.

- Math -
**Shannon**, Sunday, December 5, 2010 at 3:51pmOk so it would be P(B)=0.8, the probability that the grade is not a B.?

I hope this is right now, if it isn't I give up....lol !

- Math -
**MathMate**, Sunday, December 5, 2010 at 5:13pmDon't give up, you're right.... almost!

What Jen showed you to do was

P(not B), which equals 0.8

("...grades that aren't B's...")

there is only one grade B, so it is 1/5, there are 4 grades that are not B, so

P(not B)=4/5=0.8

Sorry if it was too confusing, hope it's more clear now.

**Related Questions**

Math 157-1 - Use the data in the grade-distribution Use the data in the grade-...

Math - Use the data in the grade-distribution table below to construct a circle ...

Math - Use the data in the grade-distribution table below to construct a circle ...

working with data - josephs final averages in science class are shown in the ...

statistics - After years of data collection by college students, it has been ...

Math - average grade - Does anyone know how to calculate average point grade? I ...

Math - Approximately 15% of the students in ST130 obtain A grade. If 3 students ...

business statics - a random sample of the grade of 78 students is taken. what is...

math - Mr. Doodle’s grade distribution over the past 3 years for a course in ...

Math - Mr. Doodle’s grade distribution over the past 3 years for a course in ...