Answer:
677 units
At $2.80, the forecast for sales is 677 units
Explanation:
No Price (x) Number Sold (y) xy x² y²
($) ($) ($) ($)
1 2.7 760 2052 7.29 577600
2 3.5 510 1785 12.25 260100
3 2 980 1960 4 960400
4 4.2 250 1050 17.64 62500
5 3.1 320 992 9.61 102400
6 4.05 480 1944 16.4025 230400
∑ 19.55 3300 9783 67.1925 2,193,400
Y = a + bX
Where a = {(∑y)(∑x²) - (∑x)(∑xy)} / {n(∑x²) - (∑x)²}
b = {n(∑xy) - (∑x)(∑y)} / {n(∑x²) - (∑x)²}
a = {(3300*67.1925) - (19.55*9783)} / {(6*67.1925) - 19.55²}
= {221,735.25 - 191,257.65} / {403.155 - 382.2025}
= 30,477.6/20.9525
= 1,454.60
b = {(6*9783) - (19.55*3300)} / 20.9525
= {58,698 - 64,515} / 20.9525
= -5,817/20.9525
= -277.62
putting the equation together:
Y = 1454.60 + (-277.62)X
∴ when x = $2.80
Y = 1454.60 - 277.62(2.80)
= 1454.60 - 777.34
= 677.26 ≈ 677 units
