What is the formula for the confidence interval? Then, define what each variable represents.

The confidence interval for a (1-α) % confidence level is given by

(θ0 - Z α/2 σ/√n, θ0 + Z α/2 σ/√n)

θ0 is the measured statistic, Z α/2 is the cutoff/critical value, and σ / √n is the standard error. σ is the population standard deviation (if known) or can be estimated by a sample standard deviation. n is the sample size. The cutoff value depends on the test you wish to use, and θ0 depends on the statistic you wish to estimate.