Afterwards you can design a digital filter with DSP.jl, apply it without phase distortion, and verify in the spectrum what it removed and what it kept.
Afterwards you can describe two samples in Julia, test whether they differ with HypothesisTests.jl, and report the effect size with a confidence interval.
Afterwards you can read a table into a Julia DataFrame, select by column and condition, handle missing values deliberately, and average by hour or group.
Afterwards you can say what a Fourier transform computes, read an amplitude spectrum, and tell how long a record you need to separate two nearby frequencies.
Afterwards you can fit a model to data with known uncertainties using LsqFit, report parameter errors you can defend, and shade a confidence band.