MeanOfThree.java:$9$: error: cannot find symbol

double val$1=$ scn$.$nextDouble$()$;

$^$

symbol: variable scn

location: class MeanOfThree

MeanOfThree.java:$12$: error: cannot find symbol

double val$2=$ scn$.$nextDouble$()$;

$^$

symbol: variable scn

location: class MeanOfThree

MeanOfThree.java:$15$: error: cannot find symbol

double val$3=$ scn$.$nextDouble$()$;

$^$

symbol: variable scn

location: class MeanOfThree

$3$ errors

What exactly do I do in this circumstance? The mean of three numbers, num$1,$ num$2,$ and num$3,$ is given by meanOfThree $=(\frac{\text{n}\text{u}\text{m}1+}{3\mathrm{.}0}$

$um2+$

$um3).$ Read

double variables num$1,$ num$2,$ and num$3$ from input, respectively. Then, compute meanOfThree using the formula. Finally, output

"Mean is $"$ followed by the value of meanOfThree to four digits after the decimal point. End with a newline.

Ex: If the input is $21\mathrm{.}015\mathrm{.}018.0,$ then the output is:

Mean is $18\mathrm{.}0000$

Note: printf$()$ can be used with $"\%\mathrm{.}4$f$"$ to output a double to $4$ digits after the decimal point.

$//$ User enters $3$ numbers and read input as val

system.out.println$("$Enter first number:"$)$;

double val$1=$ scn$.$nextDouble$()$;

System.out.println$("$Enter second number:"$)$;

double val$2=$ scn$.$nextDouble$()$;

System.out.println$("$Enter third number:"$)$;

double val$3=$ scn$.$nextDouble$()$;

$//$ Calculte the mean of the three numbers

double meanOfThree $=($val$1+$ val$2+$ val$3)/3\mathrm{.}0$;

$//$ Print the mean value formatted to four decimal places

System.out.printf$("$Mean is $\%\mathrm{.}4$f

$",$ meanOfThree$)$;

$\}$

$\}$