Skip to main content

Table 2 The four predictive models

From: The spread of COVID-19 outbreak in the first 120 days: a comparison between Nigeria and seven other countries

Model

Equation

df

Linear

Nx = a + bx + ε

1

Quadratic

Nx = c + dx + ex2 + ε

2

Cube polynomial

Nx = f + gx + hx2 + jx3 + ε

3

Exponential

Nx = kexp(mx) + ε

1

  1. where a, c, f and k are intercepts; b, d, e, g, h, j and m are slopes which are estimated by least square estimation, x is the time-point and ɛ’s are mutually uncorrelated random errors with mean (0) and common variance (σ2); df is the degree of freedom
Back to article page

BMC Public Health

ISSN: 1471-2458

Contact us