<span># of books = 4 ; original cost = 4*9=36; savings = 0.10*36= 3.60
</span>
<span># of books = 2 ;original cost = 2*20=40; savings = 0.20*40= 8.00
</span>
<span>Percent savings:
original total cost=$76
Total savings = $11.60
Percent savings: 11.60/76 = 0.1526..= 15.26%</span>
We have the following data:
Margin of Error = E = 2.7 % = 0.027
Sample size = n = 900
Proportion of adults in favor = p = 60% = 0.6
We need to find the confidence level. For this first we need to find the z value.
The margin of error for a population proportion is given as:

Using the values, we get:
As, seen from the z table, z=1.65 corresponds to the confidence level 90%. So, the answer to this question is option B
Answer:
27.2 ft
Step-by-step explanation:
Let's set up a ratio that represents the problem:
Object's Height (ft) : Shadow (ft)
Substitute with the dimensions of the 34 foot pole and its 30 foot shadow.
34 : 30
Find the unit rate:
The unit rate is when one number in a ratio is 1.
Let's make the Shadow equal to one by dividing by 30 on both sides.
Object's Height (ft) : Shadow (ft)
34 : 30
/30 /30
1.13 : 1
Now, let's multiply by 24 on both sides to find the height of the tree.
Multiply:
Object's Height (ft) : Shadow (ft)
1.13 : 1
x24 x24
27.2 : 24
Therefore, the tree is 27.2 feet tall.