$7.$ Write two functions that complete the following tasks respectively:

a$.(5$ points$)$ Write a function to compute the squared value of any x or any element in x$.$ x can have a type of float, list or array. If the type of x is not float, list nor array, return a string $$Wrong input type!$$

Once done, give a demonstration of using the function.

b$.(5$ points$)$ Write a function output the descriptive statistics of the daily returns in financial$\_$data including their minimum, median, mean, maximum, standard deviation and pair$-$wise correlations.