Answer: 1692
Step-by-step explanation:
Formula to find the sample size :

Given : Confidence level : 
⇒ significance level =
z-value for 90% confidence interval (using z-table)=
Prior estimate of the population proportion (p) of customers who keep up with regular vehicle maintenance is unknown.
Let we take p= 0.5
Margin of error : E= 2%=0.02
Now, the required sample size will be :

Simplify , we get

Hence, the required sample size = 1692
Answer:

Step-by-step explanation:
X = shorter piece
y = longer piece = 5x
shorter piece + longer piece = 60
x + 5x = 60
6x = 60
x = 60/6
x = 10 in. <== shorter piece
y = 5x
y = 5(10)
y = 50 in. <== longer piece
Answer:
4x²
Step-by-step explanation:
Your equation is 4x² - 6x² + 7x² - 20x² + 19x².
Since they all have the same variable, simply combine them all to find your answer.
4x² - 6x² + 7x² - 20x² + 19x²
-2x² + 7x² - 20x² + 19x²
5x² - 20x² + 19x²
-15x² + 19x²
4x²