To find the margin of error, multiply the z-score by the standard deviation, then divide by the square root of the sample size.The z*-score for a 90% confidence level is 1.645.The margin of error is 0.20.The confidence interval is 48.3 to 48.7.48.8 is not within the confidence interval.
For this case we must factor the following polynomial:

We can take common factor x:

To factor the expression within the parenthesis, we must find two numbers that when multiplied give 49 and when added together, 14 are obtained. These are: 7 and 7.

Thus, the expression is factored as:

Answer:

Q1
the clothes are on 45% discount, wich mean they become 55% of their original price.
30× 55% =16.5
64×55%=35.2
the new salary is 103% of the original
10×103% = 10.3
11600×103% = 11,948
Q2:
1+0.24= 1.24
1- 0.27= 0.73
86×140%= 120.4
440×119%= 523.6
82×90% = 73.8
480× 73%= 350.4