Answer:
The lower class boundary for the first class is 140.
Step-by-step explanation:
The variable of interest is the length of the fish from the North Atlantic. This variable is quantitative continuous.
These variables can assume an infinite number of values within its range of definition, so the data are classified in classes.
These classes are mutually exclusive, independent, exhaustive, the width of the classes should be the same.
The number of classes used is determined by the researcher, but it should not be too small or too large, and within the range of the variable. When you decide on the number of classes, you can determine their width by dividing the sample size by the number of classes. The next step after getting the class width is to determine the class intervals, starting with the least observation you add the calculated width to get each class-bound.
The interval opens with the lower class boundary and closes with the upper-class boundary.
In this example, the lower class boundary for the first class is 140.
The linear equation used to solve the problem is t = 2 + 1.29a and total cost to download 30 songs is $ 40.7
<em><u>Solution:</u></em>
Given that music app charges $2 to download the app plus $1.29 per song downloaded
To find: write and solve a linear equation to find the total cost to download 30 songs
Let us first write a expression for total cost
Let "a" be the number of songs downloaded
So we can frame a equation as:
total cost = initial charge + cost of 1 song download x number of songs downloaded

total cost = 2 + 1.29a
If "t" represents the total cost, then the linear equation is:
t = 2 + 1.29a
<em><u>finding the total cost to download 30 songs:</u></em>
Here a = 30
Substitute a = 30 in above formula
total cost = 2 + 1.29(30)
total cost = 2 + 38.7
total cost = 40.7
Thus total cost to download 30 songs is $ 40.7
X^2-y^2
you would get x^2+xy-xy+y^2
the xy and -xy cancel