Answer:

Step-by-step explanation:
"At least" is inclusive, so you can be 21 years old.
The normal rule to remember is 68-95-99.7, i.e. plus or minus three sigma corresponds to 99.7% of the probability. That leaves 0.3% in the two tails, or 0.15% in the tail above 3 sigma.
Answer: 0.15%
Larger I think, sorry if that’s wrong.
Answer: 9/100
Step-by-step explanation:
Probability of people own a cat:
P(cat)=30/100=0.3
Probability of people own a bird:
P(bird)=3/100=0.03
Probability of both own a cat and a bird
P(cat and bird)=(30/100) × (3/100)
=90/1000=9/100=9%
Answer:
X=1/5
Step-by-step explanation:
7×-2×-10=-9
5×=-9 +10
5×/5=1/5
×=1/5