The sample size should be 250.
Our margin of error is 4%, or 0.04. We use the formula

To find the z-score:
Convert 98% to a decimal: 0.98
Subtract from 1: 1-0.98 = 0.02
Divide both sides by 2: 0.02/2 = 0.01
Subtract from 1: 1-0.01 = 0.99
Using a z-table (http://www.z-table.com) we see that this value has a z-score of approximately 2.33. Using this, our margin of error and our proportion, we have:

Divide both sides by 2.33:

Square both sides:

Multiply both sides by n:

Divide both sides to isolate n:
Answer:
6.66 yards of ribbon.
Step-by-step explanation:
If she has 10 yards of ribbon and divides it equally into three parts, those 3 parts would each be 3.33 yards long or 3 (1/3) yards long.
If she uses two of those parts on gifts, then she would use 3.33 x 2 or 6.66 yards of ribbon.
Answer:
12.63 km/hr
Step-by-step explanation:
Given the distance=240km
At 12 km/hr it will take =240/12 =20
time for Express train = 20-1=19
speed=240/19=12.63...km/hr
For this case, the first thing we must do is define a variable.
We have then:
x: real number
Now we write the expression:
-8 / (x + 3)
The number x can be all real different from minus three.
Answer:
-8 / (x + 3)
With x different from -3.