Resampling sounds from 8bit unsigned 11025 to 16bit signed 44100

I use this method for resampling with sinus amplitude:

Input sound:
8Bitu: 0 10 30 40 30

Output sound:
8Bitu low freq: 0 10 30 40 30
16Bitu low freq: 0 10256=2560 30256=7680 40256=9580 30256=7680
First subsample =first_low_sample
Second subsample=first_low_sample x 0.85 + second_low_sample x 0.15
Third subsample =first_low_sample x 0.5 + second_low_sample x 0.5
Four subsample =first_low_sample x 0.15 + second_low_sample x 0.85
16Bitu hi freq: 0 326 1280 2176 2560 3328 5220 6912 7680 7965 8630 9295 9580 9295 9630 7965 7680
And end step(16Bitu to 16Bits) is sub sample - 32768