Below is a table showing the mean monthly maximum temperatures for a city in Greece.
Month
Jan
Feb
Mar
Apr
May
Jun
July
Aug
Sept
Oct
Nov
Dec
Temperature / ∘C
15
14
15
18
21
25
27
26
24
20
18
16
(1) Draw a scatter diagram of the data.
(2) What features of the data suggest a trigonometric model is appropriate?
(3) Model the data with a sine function of the form T≈asin(b(t−c))+d, where Jan≡1, Feb≡2, and so on. Without using technology, estimate: (i) b, (ii) a, (iii) d, and (iv) c.
(4) Use technology to check your model. How well does your model fit?