Set up the equation by writing the number of students in the ratio as a fraction:
3/4= (245-x)/x Cross multiply:
3x= 4(245-x) Multiply on right:
3x= 980-4x Add 4x on both sides:
7x= 980 Divide both sides by 7:
x= 140 this is how many girls there are. And:
245-140= 105= boys
Answer:
m<1 = 105°
m<2 = 75°
Step-by-step explanation:
Since lines c and d are parallel to each other, therefore:
m<2 = 75° (corresponding angles are congruent)
m<1 + m<2 = 180° (linear angle pair)
Substitute
m<1 + 75° = 180°
Subtract 75 from both sides
m<1 = 180° - 75°
m<1 = 105°
I’m not sure what you’re options are but an equation in Y=mx+b form for this would be y= -3/2x + 5
M is always the slope
B is always the y intercept
Answer: C. there is still not enough evidence to conclude that the time series is stationary.
Step-by-step explanation: First thing to note for a time series plot is that it is required to select a suitable forecast method for the data set being considered.
A stationary time series means that the process generating the data set has a constant mean and the variations are constant over time. This means all evidence is present leading to the conclusion that the entire time series is stationary. A stationary time series thus exhibits an horizontal pattern which enables an appropriate forecast method to be selected for this type of pattern.
A horizontal pattern of a time series plot indicates that a data set fluctuates around a constant mean for a period of time. This period of time may however not be the entire time of the time series or take the entire data set into consideration and might just be a reflection of a portion of the time series hence why it can not be explicitly considered to be stationary. This means that a horizontal pattern can change into a seasonal or trending pattern if more variables/data are added over time.
For instance, a manufacturer sells a certain amount of products over a 10 week period and the resulting pattern of a time series plot is horizontal, then from the 11th week to the 15th week he gets a sharp and continuous increase in sales. This change in level will therefore change the time series plot from horizontal to trending making it more difficult to select a suitable forecast method.
The equation in slope intercept form is y= 1x - 70