Please help me with this one!

For each person, there are only two possible outcomes. Either they are tasters, or they are not. The probability of a person being a taster is independent of any other person. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The variance of the binomial distribution is:

$V(X) = np(1-p)$

It is known that 70% of the American people are "tasters" with the rest are "non-tasters". Suppose a genetics class of size 20

This means that $p = 0.7, n = 20$

So

$V(X) = np(1-p) = 20*0.7*0.3 = 4.2$

The variance for the number of tasters is 4.2

7 0

3 years ago

A box contains 2 dozen pairs of contact lenses ,of which 8 pairs are tinted. A pair of contact lenses is drawn at random from th

tia_tia [17]

Answer:

$\dfrac{2}{3}.$

Step-by-step explanation:

It is given that a box contains 2 dozen pairs of contact lenses ,of which 8 pairs are tinted.

1 dozen = 12 units

Total pairs of contact lenses $=2\times 12 = 24$

Tinted pairs of contact lenses = 8

Pairs of contact lenses not tinted = 24 - 8 = 16

If a pair of contact lenses is drawn at random from the box, then we need to find the probability that it is not tinted.

$P(\text{Not tinted})=\dfrac{\text{Pairs of contact lenses not tinted}}{\text{Total pairs of contact lenses}}$

$P(\text{Not tinted})=\dfrac{16}{24}$

$P(\text{Not tinted})=\dfrac{2}{3}$

Therefore, the required probability is $\dfrac{2}{3}.$

4 0

3 years ago

A gardener is planting two types of trees:Type A is three feet tall and grows at a rate of 15 inches per year.Type B is four fee

Sliva [168]

First, construct two equations.
Then, equal the two equations to each other like this -

x will be the years.

Type A. Type B

3x + 15 = 4x + 10
- 15. - 15

3x = 4x - 5
-4x. -4x

-x = -5
-x/-1 = -5/-1
x = 5

Check:

3(5) + 15 = 4(5) + 10
15 + 15 = 20 + 10
30 = 30

Therefore, the trees will be the same height in 5 years.

7 0

3 years ago