Answer:
<u>The sum of their ages now is 13</u>
Step-by-step explanation:
Dally's age = x
Dilly's age = x - 7
In 4 years time Dilly will be half Dally’s age, therefore:
Dilly's age plus four equals to half of Dally’s age plus four,
replacing with the values and variables we know:
x - 7 + 4 = (x + 4) /2
x - 3 = (x + 4) /2
2x - 6 = x + 4 (Multiplying by 2 at both sides)
2x - x = 4 + 6 (Like terms)
x = 10 ⇒ x - 7 = 3
<u>The sum of their ages now is 13 (10 + 3)</u>
Answer:
Therefore, we use the linear depreciation and we get is 17222.22 .
Step-by-step explanation:
From Exercise we have that is boat $250,000.
The straight line depreciation for a boat would be calculated as follows:
Cost boat is $250,000.
For $95,000 Deep Blue plans to sell it after 9 years.
We use the formula and we calculate :
(250000-95000)/9=155000/9=17222.22
Therefore, we use the linear depreciation and we get is 17222.22 .
Answer:
The total change that will likely occur in 2 years is 
mg/L
Step-by-step explanation:
Given : The first year, they found the chloride concentration changed by 
mg/L .
It is estimated that the chloride concentration will change 
mg/L the next year.
To find : What is the total change that will likely occur in 2 years?
Solution :
The chloride concentration changed by 
mg/L in first year.
The chloride concentration will change 
mg/L the next year.
The total change that will likely occur in 2 years is
In a mixed fraction - mg/L
The point r(-6,-5) lies on the circle.
Explanation
Given that the center of the circle=(-2,-2)
diameter=10 units
we have to determine which point among the given points lies on the circle.
radius=diameter/2=10/2=5 units
let (x,y) be a point on the circle
The distance between the center and (x,y) is equal to the radius of the circle
The distance between them=
squaring both sides 
The option (-6,-5) satisfies the equation
therefore the point that lies on the circle is (-6,-5)
Answer:
The standard deviation of that data set is 3.8
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 55
95% of the data fall between 47.4 and 62.6. This means that 47.4 is 2 standard deviations below the mean and 62.6 is two standard deviations above the mean.
Using one of these points.
55 + 2sd = 62.6
2sd = 7.6
sd = 7.6/2
sd = 3.8
The standard deviation of that data set is 3.8
