Answer:
np = 81 , nQ = 99
Step-by-step explanation:
Given:
X - B ( n = 180 , P = 0.45 )
Find:
Sampling distribution has an approximate normal distribution
Computation:
nP & nQ ≥ 5
np = n × p
np = 180 × 0.45
np = 81
nQ = n × (1-p)
nQ = 180 × ( 1 - 0.45 )
nQ = 99
Let x= number rows
Then x + 5 = number of seats per row
x(x+5) = 126
X^2 + 5x = 126
x^2 + 5x -126 = 0; now factor or use quadratic:
(x+14)(x-9) = 0; so the answers are either -14, or 9, and since -14 is not possible in this case because you can't have a negative number of rows, the answer is 9 rows.
Check work: number of rows = 9, number of seats per row = 9+ 5= 14, and 9 x 14 = 126
X= y(d-b) over a-c would be the answer