Underfull \hbox when creating table containing much text

Question

I am completely new to LaTeX and how to create tables in this environment. Currently, I am trying to create a table that contains much text in each cell using tabularx. The output does not look too bad, a lot of Underfull \hbox (badness 10000) in paragraph errors are created in the log related to the individual cells.

Is there any way to amend this?

I am trying to make following table:

\documentclass[12pt,a4paper]{article}
\usepackage[onehalfspacing]{setspace}
\usepackage{booktabs,tabularx}

\begin{document}
\begin{table}
\centering
\caption{Diagnostic tests overview}
\setlength{\tabcolsep}{10pt}
\begin{tabularx}{\textwidth}{X p{2.8cm} p{2.8cm} p{2.8cm}}
\toprule
Test & Diagnose & $H_0$ & $H_1$ \\
\midrule
F-test & Joint significance & $\beta_0=\beta_1=\ldots=\beta_i=0$ & Some or all $\beta_i\neq0$ \\[0.7cm]
Jarque-Bera & Normality & No skewness or excess kurtosis & Non-normality \\[0.7cm]
White & Hetero\-skedasticity & Homo\-skesdasticity & Hetero\-skedasticity \\[0.7cm]
White Cross-Products (X) & Hetero\-skedasticity & Homo\-skesdasticity & Hetero\-skedasticity \\[0.7cm]
Breusch-Godfrey & Autocorrelation & No autocorrelation & Autocorrelation \\[0.7cm]
Ramsey\-RESET 1 & Misspecification & Correct specification & Misspecification \\[0.7cm]
Ramsey\-RESET 2 & Misspecification & Correct specification & Misspecification \\
\bottomrule
\end{tabularx}
\end{table}
\end{document}

Answer 1

The underful boxes are because LaTeX is trying to justify the text in the narrow columns with very little text. using

\begin{tabularx}{\textwidth}{
>{\raggedright\arraybackslash}X 
*{3}{>{\raggedright\arraybackslash}p{2.8cm}}
}

sets the text ragged and the underfull warnings go away, but you get some overfull warnings

Overfull \hbox (2.05496pt too wide) in paragraph at lines 25--25
[]|\OT1/cmr/m/n/12 Misspecification|

as that word is wider than the column. If you use

\begin{tabularx}{\textwidth}{
>{\raggedright\arraybackslash}X 
*{3}{>{\raggedright\arraybackslash}p{2.9cm}}
}

LaTeX goes very quiet.