问一个很简单的问题，概率分布图怎么表示

>> x=randn(300,1);
>> dfittool(x)


%Click "New Fit..." and "Apply",then it returns


%The Results pane displays the mean and standard deviation of the normal distribution that best fits x, as shown in  follow
Distribution:    Normal
Log likelihood:  -400.751
Domain:          -Inf < y < Inf
Mean:            -0.0170083
Variance:        0.849699

Parameter  Estimate    Std. Err.
mu         -0.0170083  0.0532196
sigma        0.921791  0.0377264

Estimated covariance of parameter estimates:
       mu            sigma      
mu       0.00283233  5.16186e-020
sigma  5.16186e-020    0.00142328

%Get help by typing "doc disttool" at the command line.