How is the sex of the child determined in human beings?

(N/A) In human beings,females have two $X$ chromosomes and males have one $X$ and one $Y$ chromosome. Therefore,the genotype of females is $XX$ and that of males is $XY$.
During gametogenesis,gametes receive half of the chromosomes. Male gametes contain $22$ autosomes and either an $X$ or a $Y$ sex chromosome.
Types of male gametes: $22+X$ or $22+Y$.
Since females have $XX$ sex chromosomes,all their gametes contain an $X$ sex chromosome.
Type of female gamete: $22+X$.
Thus,the mother always contributes an $X$ chromosome. The sex of the child is determined by the type of male gamete ($X$ or $Y$) that fertilizes the female egg (which always carries an $X$ chromosome). If an $X$-bearing sperm fertilizes the egg,the zygote becomes $XX$ (female). If a $Y$-bearing sperm fertilizes the egg,the zygote becomes $XY$ (male).