Answer:
The variance for the number of tasters is 4.2
Step-by-step explanation:
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:

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 
So

The variance for the number of tasters is 4.2
86+08p because both have the answer
Answer:
z+150=180
z=30
then again
x+x+20+30=180
2x=180-50
2x=130
x=130/2
x=65
Step-by-step explanation:
x
Answer:
"Dominic lived in Spain for 13 months and Columbia for 7 months."
Step-by-step explanation:
let months stayed in spain be "s" and months stayed in columbia be "c"
We can write 2 equations.
Since, lived in Spain and Columbia for a total of 20 months, we can write:
s + c = 20
Also, since 120 words per month in Spain and 150 words per month in Columbia for a total of 2610 new words, we can write:
120s + 150c=2610
Solving first for s:
s = 20 - c
Putting in 2nd and solving:
120(20 - c) + 150c = 2610
2400 - 120c + 150c = 2610
30c = 210
c = 7
Now,
s = 20 - c = 20 - 7 = 13
So
"Dominic lived in Spain for 13 months and Columbia for 7 months."