# Math Help - Finding the indicated probability

1. ## Finding the indicated probability

1. In a certain college , 33% of the physics majors belong to ethnic minorities. If 10 students are selected at ranom from the physics majors, that is the probability that no mre than 6 belong to an ethnic minoirty

Is this right?
p(No more that 6 belong to ethnic minority)
N=10
P=.33
X to r = 5

In TI-84 I compute
Bicdf(10,.33,5=.9267995433 or .9268 (R/up)

2. Find the probability of at least 2 girls in 10 births. Assume that male and female births are equal likely and that the births are independent events?

Would I use Binominalcdf or Pdf....Im guessing?

No Clue.... Need definitive help

3.The volumes of soda in quart soda bottles are normally distributed with a mean of 32.3 oz and a std deviation 1.2 oz . What is the probability that the volume of soda in a randomly selected bottle will be less than 32 oz

No Clue...need definitive help..... do know it will be negative side I know I would have to find what my Probability is, Sigma, What Z is ....can anyone help

2. Originally Posted by Cribster01
1. In a certain college , 33% of the physics majors belong to ethnic minorities. If 10 students are selected at ranom from the physics majors, that is the probability that no mre than 6 belong to an ethnic minoirty

Is this right?
p(No more that 6 belong to ethnic minority)
N=10
P=.33
X to r = 5

In TI-84 I compute
Bicdf(10,.33,5=.9267995433 or .9268 (R/up)

Mr F says: $Pr(X \leq 6) \Rightarrow \,$ binomcdf(10, 0.33, 6)

2. Find the probability of at least 2 girls in 10 births. Assume that male and female births are equal likely and that the births are independent events?

Would I use Binominalcdf or Pdf....Im guessing?

No Clue.... Need definitive help

Mr F says: $Pr(X \geq 2) = 1 - Pr(X \leq 1) \Rightarrow \,$ 1 - binomcdf(10, 0.5, 1)

3.The volumes of soda in quart soda bottles are normally distributed with a mean of 32.3 oz and a std deviation 1.2 oz . What is the probability that the volume of soda in a randomly selected bottle will be less than 32 oz

Mr F asks: Are you doing this one using technology? If so, what calculator? TI-83? TI-89? ...... if you're using technology you don't need to convert to z-value etc. (only do this if you're using tables).

No Clue...need definitive help..... do know it will be negative side I know I would have to find what my Probability is, Sigma, What Z is ....can anyone help
..

3. I am using TI-84 as instructed by professor

Can U help?

4. Originally Posted by Cribster01
[snip]
3.The volumes of soda in quart soda bottles are normally distributed with a mean of 32.3 oz and a std deviation 1.2 oz . What is the probability that the volume of soda in a randomly selected bottle will be less than 32 oz
[snip]
normalcdf(lower value, upper value, mean, standard deviation) gives the probabilty that a normally distributed random variable will lie between given lower and upper values.

Normally distributed with a mean of 32.3 and a std deviation 1.2 and requiring $\text{Pr}(-\infty < X < 32.3) \Rightarrow \,$ normalcdf(-E99, 32, 32.3, 1.2)
where -E99 is a 'fudge' for -oo.