This appears to be the mean and variance of the population distribution.

This information is in the show file (

https://conquestmanual.acer.org/s4-00.html#show). You can output this file, after estimation, as a text file, an excel file, or directly to the screen. You are looking for table 3: "Estimates for each of the parameters in the population model and reliability estimates.".

The mean of the population is given under Regression Coefficients ("CONSTANT"), and the variance is given int he unconditional covariance/correlation matrix ("Variance"). You will need to convert the latent variance to SD and SE (note the number of cases in the model is given in table 1, see "Cases in estimation")

Note if you have a complex population model (e.g., more than an intercept-only model), then it may be easier to use the command "descriptives":

https://conquestmanual.acer.org/s4-00.html#descriptives.

"Descriptives" will directly report the mean, variance, SD for you (and the error associated with each). You can also calculate other statistics, like percentiles and classification above and below benchmarks.

Screenshot is attached.