ANSWER PLEASE FINAL DUE IN 3 HOURS

Suppose a normal distribution has a mean of 120 and a standard deviation of 10. What is P(x ≥ 130)?

A.
0.475

B.
0.84

C.
0.16

D.
0.975

B

Step-by-step explanation:

First thing to do here is to calculate the z-score

Mathematically;

z-score = (x-mean)/SD

here, x = 130, mean = 120 and SD = 10

Substituting these values

z-score = (130-120)/10 = 10/10 = 1

So the probability we want to calculate is;

P(z ≥ 1) = 1 - P(z <1)

From standard score table, P(z <1) = 0.15866

P(z ≥ 1) = 1-0.15866 = 0.84134

d) by the cross product property, ab^2 = bc multiplied by ad

step-by-step explanation:

we are given

in the given triangle abc

angle a is 90° and segment ad is perpendicular to segment bc

we can see that

triangle(abc) and triangle(abd) are similar because they have common side and same angle (90 degree)

so, triangles(abc) and abd are similar

since, they are similar

so, the ratio of their sides must be equal

we get

now, we can cross multiply

and we get

so, this could be step to prove it

step-by-step explanation: so we look at the formula un = a + (n-1)d

un is the amount of seats

n is the nth term aka row number

a is the original sequence/row number

d is the difference between each term

so in this a=22 d=6 and n can remain as n because we are simply formjng a rule

lets put these in the equation

un=22+(n-1)(6)

this is your answer to part a

however

lets double check that this is correct, we'll try putting it into the second term

un=a+(n-1)d

u2=22+(2-1)(6)

u2=22+6

u2=28

as the question said the second row has 28 seats so now we know the formula we made is correct.

as for part b

un=a+(n-1)

its asking us to find a row with 100 seats.

remember un was the amount of seata so all we do is substitute this in.

un=100 a=22 d=6

un=a+(n-1)d

100=22+(n-1)(6)

so now we simplify to find n which is the row number.

100-22=22+(n-1)(6)-22

78=(n-1)(6)

78/6=(n-1)(6)/6

13=n-1

13+1=n-1+1

14=n

so now we know that in the 14th row there is 100 seats.

hope this and that you understood! its my first time using the app or anyone out on here : p its also me to revise so a bunch! ask more questions if you dont understand ☺