Answer:
a. 
b.

c. For David to achieve three hundred dollars, he would have to save approximately 5 months
Step-by-step explanation:
A. David requires three hundred dollars, this is his goal, indicating the three hundred must be alone. For the inequality sign, the statement says that he "requires at least $300", meaning that he would have to maintain three hundred dollars or his amount could go greater than $300. Therefore, the inequality sign should be "≥" or "greater than or equal to". We also know that David can save 63 dollars per month, meaning that there should be a variable next to 63 so we could replace "x" with any number to solve our inequality. This should leave us with the following inequality :
63x ≥ 300
B. To solve the inequality, we need to get x alone, to do so, divide 63 by both sides,


To make it easier, we can round "4.76" to 5.

C. Already shown in the answer spot
Answer:
d. ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b) = ( 63.9, 66.7)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 65.3
Standard deviation r = 5.2
Number of samples n = 36
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
65.3+/-1.645(5.2/√36)
65.3+/-1.645(0.866667)
65.3+/-1.42567
65.3+/-1.4
= ( 63.9, 66.7)
Therefore at 90% confidence interval (a,b) = ( 63.9, 66.7)
Here we want to see which one of the given graphs is the one with the correct relationship between distance in centimeters and meters. We will see that the correct option is the first graph.
<h3>Working with changes of scale.</h3>
So we know that each centimeter on the map must represent 4 meters in reality, this is a change of scale, so the scale is:
1cm = 4m
First, this relation is linear (each centimeter will always be equal to 4 meters) so the two bottom options that are not linear can be discarded, so we only have the first and second graph.
If you read them, you can see that in the second one 1 meter is equivalent to something near 5 cm, so this is also incorrect.
The only graph that shows a correct scale is the first one, where for each increment of 1 unit on the horizontal axis (the one in centimeters) we have an increase of 4 m (estimated). This means that 1cm = 4m, as in our change of scale.
So the correct option is the first graph.
If you want to learn more about changes of scale, you can read:
brainly.com/question/9302261
Answer:
36 pi
Step-by-step explanation:
Aera of sphere is : 4 *pi *r^2
A=4 *pi*9=36pi=113