Answer:
b because it just is
Step-by-step explanation:
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.
Answer:
Step-by-step explanation:
1. sinФ = cos 25
25 ° is in the between 0 and 90°
therefore it can simply represent
cosФ= sin (90-Ф) = sin (90 - 25) = sin 65
2. sin(Ф/3 + 10) = cos Ф
cos Ф = sin (90 -Ф)
sin(Ф/3 + 10) = cos Ф
sin(Ф/3 + 10) = cos Ф = sin(90-Ф)
Ф/3+10=90-Ф
10Ф+3/30 = 90-Ф
10Ф+3 = 30(90-Ф)
10Ф+3 = 2700-30Ф
10Ф+30Ф=2700-3
40Ф = 2697
Ф = 2697 / 40 = 67.425 ≅ 67.4°
Answer:
A 6.4
Step-by-step explanation:
(4/5)/(1/8) this is the answer