Answer:
The sample size needed to be taken is approximately 74.
Step-by-step explanation:
To get alpha; we have 1 - 0.95 = 0.05
Therefore, 
The we look up z* in a Standard Normal table where α = 0.025 area in each tail.
From the table, z* = 1.96
From the question variance is 484, then the standard deviation is 22
Standard deviation = 
And margin of error is 5 or less
The formula for margin of error is given as:
margin of error = 

The approximate value of n is 74.
Answer:
29/400
Step-by-step explanation:
.0725 = 725 /10 000 = 29/400
Answer:
x=-5, x=9
Step-by-step explanation:
we know that
The formula to solve a quadratic equation of the form
is equal to
in this problem we have
equate to zero
so
substitute in the formula
therefore
The solutions are x=-5, x=9