Answer:
y = 54/25
Step-by-step explanation:
y = p×q^(x-1)
when x = 1 then y = 10
so,
10 = p×q^(1-1)
or, 10 = p×1
or, p = 10
when x = 6 then y = 0.7776
0.7776=p×q^(6-1)
or, 0.7776=p×q^5
or, 0.7776=10×q⁵
[0.7776 = 7776/10000 = 486/625]
or, 486/625 = 10×q⁵
or, 486/6250=q⁵
or, [tex] \frac{ \sqrt[5]{486} }{ \sqrt[5]{6250} } = q[/tex]
or, [tex]q = \frac{3 \sqrt[5]{2} }{5 \sqrt[5]{2} } [/tex]
or, q = 3/5
so, when x = 4
y = p×q^(x-1)
y = 10×(3/5)^(4-1)
y = 10×(3/5)^3
y = 10×27/125
y = 54/25
