Answer:
a)Both X and Y can be well approximated by normal random variables.
Step-by-step explanation:
For each individual, there are only two possible outcomes. Either they are right-handed, or they are left-handed. This means that we can solve this problem using concepts of the binomial probability distribution.
Binomial probability:
Probability of exactly x sucesses on n repeated trials, with probability p.
The binomial probability can be well approximated by normal random variables, using the expected value
and the standard deviation 
Let X be the number of males (out of the 100) who are left-handed.
and
. Can be well approximated.
Let Y be the number of females (out of the 80) who are left-handed.
and
. Can be well approximated.
The correct answer is
a)Both X and Y can be well approximated by normal random variables.
Answer:
(2,-7)
Step-by-step explanation:
Use the midpoint formula! (Attached is a picture of it!)
1) Plug in the values:
(5-1)/2,(-6+-8)/2
2) Simplify:
4/2,-14/2
3) Solve:
(2,-7)
Answer:
61
Step-by-step explanation:
- 13 - 1 = 12
- 12 ÷ 2 = 6
- Put 6 and 1 together: 61
Therefore, the number is 61
Let's check:
- 6 × 2 = 12
- 12 + 1 = 13
The sum of the two digits is 13, and we got that, so we are correct. The number is 61.