Tarantulas are 5.9 centimeters longer.
You have to perform operations inside parenthesis first:

And finally,

Answer:
1. 0.9648
2. 0.602
3. 0.0352
4. 0.398
Step-by-step explanation:
We solve using binomial probability
n = 15
P = 20% = 0.2
1. At least 1 is tight
= P(X>=1)
P(X>=1) = 1-p(X= 0)
= P(x=0)
= 15C0(0.20)⁰(1-0.20)^15-0
= 15C0(0.20)⁰(80)¹⁵
= 0.0352
P(x>=1) = 1-0.0352
= 0.9648
2.
More than 2 ties tight
P(X>2)
P(X>2) = 1-p(X<=2)
p(X<=2) = p(x=0) + p(x=1) + p(x=2)
= p(x=0) = 0.0352
p(x=1) = 15C1(0.20)¹(0.80)¹⁴
= 0.1314
p(x=2) = 15C2(0.20)²(0.80)¹³
= 0.2309
P(x>2) = 1-(0.0352+0.1314+0.2309)
= 0.602
3.
No ties is tight
P(X = 0)
= 15C0(0.20)⁰(0.80)¹⁵
= 0.0352
4.
At least 3 are not tight
This says that at most we have 3 to be too tight
= p(X<=2) = p(x=0) + p(x=1) + p(x=2)
= 0.0352+0.1319+0.2309
= 0.398
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You have to turn the 12 into 1/12 for its reciprocal. Then you do 4/9*1/12. You cancel the 4 and make it into a 1 and make the 12 into a 3. 9*3=27. So you get D: 1/27