code: def test_use_t(df):
      res = Description(df)
      res_t = Description(df, use_t=True)
      assert res_t.frame.a.lower_ci < res.frame.a.lower_ci
      assert res_t.frame.a.upper_ci > res.frame.a.upper_ci
  
file_path: statsmodels/statsmodels/stats/tests/test_descriptivestats.py
imports: import numpy
  from numpy.testing import assert_almost_equal, assert_equal
  import pandas
  import scipy.stats
  import pytest
  from statsmodels.iolib.table import SimpleTable
  from statsmodels.stats.descriptivestats import Description, describe, sign_test
label_desc: Use image node_id 7 for calling a global function with example usage: test_use_t(df) without return types