Matlap Clamped Spline : I need to solve the question on the photo with the help of matlab What am I doing wrong? Are there some who can help? Very important to me.

    clc;
    clear;
    format compact;
    T=[0 3 5 8 13]
    V=[0 225 383 623 993]
    A=[75 77 80 74 72]
    v_5=interp1(T,V,5);
    a_5=interp1(T,A,5);
    t_5=interp1(T,A,5);
    x=0:3:13;
    y=interp1(T,A,x,'spline');
    plot(T,V,'o',x,y),title('speed vs distance ')


[exp][1]


  [1]: https://i.stack.imgur.com/iqS4n.png