C++11 auto variable : float array vs auto

Size of float array declared is suing auto is different than actual size. why is it so ??

For e.g:

declaration:

float duto[] = {2.2222f,2.223f,34.5f,1.0f,9.0f};
auto dutot = {2.2222f,2.223f,34.5f,1.0f,9.0f};

Size print:

std::cout << " float array size v: " << sizeof(duto)<<std::endl;
std::cout << " auto v: " << sizeof(dutot)<<std::endl;

Output:

float array size v: 20
auto v: 16