cut, population mean and sample size in Python

Question 4

Partition the sample based on 10-year age bands, i.e. the resulting groups will consist of people with ages from 18-28, 29-38, etc. Question 4 Partition the sample based on 10-year age bands, i.e. the resulting groups will consist of people with ages from 18-28, 29-38, etc. Construct 95% confidence intervals for the difference between the mean BMI for females and for males within each age band.

df = da.copy()
df['agegrp'] = pd.cut(x=df.RIDAGEYR, bins=[18,28,38,48,58,68,78,88])
df['gender'] = df.RIAGENDR.map({1: 1, 2: 2})

dk = df[['agegrp', 'gender', 'BMXBMI']].dropna()
dk

condition = dk['gender'] == 1 # only for males
dk_male = dk[condition]
dk_male

dz_male = dk_male.groupby('agegrp').agg({'BMXBMI': [np.mean,np.std]})
dz_male # means and std for males

dk_male.groupby('agegrp').size() # sample size n for each males groups

condition = dk['gender'] == 2 # only for females
dk_female = dk[condition]
dk_female

dz_female = dk_female.groupby('agegrp').agg({'BMXBMI': [np.mean,np.std]})
dz_female # means and std for females

dk_female.groupby(['agegrp']).size() # sample size n for each females groups

#​ Function for means difference

  def find_limits_male_female (mean1, mean2, std1, std2, n1, n2):
    diff = 1.984 * np.sqrt((std1*std1 / n1) + (std2 * std2 / n2))
    low = (mean1 - mean2) - diff
    upper = (mean1 - mean2) + diff
    return (low, upper)

group1 = find_limits_male_female(27.058186,28.01943,6.679515,8.048854, 452,494)
group1

group2 = find_limits_male_female(29.697180,29.943443,6.726690,7.959097,461,488)
group2

group3 = find_limits_male_female(29.514646,31.003733,6.104950,8.044642,396,509)
group3

group4 = find_limits_male_female(29.385132,30.787361,6.151534,7.647590,417,451)
group4

group5 = find_limits_male_female(29.232462,31.054664,5.959024,7.779502,459,461)
group5

group6 = find_limits_male_female(28.720270,30.537818,5.336652, 6.780588,296,275)
group6

group7 = find_limits_male_female(27.464368,27.850000,4.695650, 5.483781,174,198)
group7

CI for 18 to 28 (0.0, 1.8)
CI for 28 to 38 (-0.7, 1.1)
CI for 38 to 48 (0.6, 2.4)
CI for 48 to 58 (0.4, 2.4)
CI for 58 to 68 (0.9, 2.7)
CI for 68 to 78 (0.8, 2.8)
CI for 78 to 88 (-0.6, 1.4)