Question

Mrs. Gomes found that 40% of students at her high school take chemistry. She randomly surveys 12 students. What is the probability that exactly 4 students have taken chemistry? Round the answer to the nearest thousandth. P (k successes) = Subscript n Baseline C Subscript k Baseline p Superscript k Baseline (1 minus p) Superscript n minus k. Subscript n Baseline C Subscript k Baseline = StartFraction n factorial Over (n minus k) factorial times k factorial EndFraction 0.005 0.008 0.213 0.227

Answer 1

Answer:

The correct answer to the following question will be "0.438".

Step-by-step explanation:

Just because Mrs. Gomes finds around 40% of students in herself high school are studying chemistry.  

Although each student becomes independent of one another, we may conclude:  

"x" number of the students taking chemistry seems to be binomial to p = constant probability = 0.40

Given:

Number of surveys

= 12

Exactly 4 students have taken chemistry:

$=P(X\leq4)$

$=P(x=0)+P(x=1)+P(x=2)+P(x=3)+P(x=4)$

$=\Sigma_{0}^{4} C_{r}(0.4)^r(0.6)^{12-r}$

On substituting the above equation, we get the probability of approximately "0.438".

So that the above would be the appropriate answer.