Answer:
a) The probability that at least 5 ties are too tight is P=0.0432.
b) The probability that at most 12 ties are too tight is P=1.
Step-by-step explanation:
In this problem, we could represent the proabilities of this events with the Binomial distirbution, with parameter p=0.1 and sample size n=20.
a) We can express the probability that at least 5 ties are too tight as:

The probability that at least 5 ties are too tight is P=0.0432.
a) We can express the probability that at most 12 ties are too tight as:

The probability that at most 12 ties are too tight is P=1.
Answer:
4 × ( 9 + 2z)
Step-by-step explanation:
36 + 8z = 4 × (9) + 4 × (2z) ; so here 4 is a common factor
= 4 × ( 9 + 2z)
we can also write it like this
36 + 8z = 2 × ( 18 + 4z)
(15√6 / √5)
<span>(15√6/√5) *(</span>√5/√5)
(15*√6*√5)/(√5*√5)
15*√30 / 5
3√30