а)

array = [1, 5, 2, 7, 3, 9, 4]
last_element = array[-1]
count_smaller = 0
for element in array:
if element < last_element:
count_smaller += 1
print("Количество элементов меньших последнего элемента: ", count_smaller)

б)

array = [1, 5, 2, 7, 3, 9, 4]
average = sum(array) / len(array)
count_bigger = 0
for element in array:
if element > average:
count_bigger += 1
print("Количество элементов больших среднего арифметического массива: ", count_bigger)