Error in angular 4: "property ... does not exist on type ..."

I'm starting with angular4 , using the angular-cli tool I generated a test project and I have a problem when I try to use the imported service method, this would be the source code:

app / student.service.ts

import { Injectable } from '@angular/core';

@Injectable()
export class EstudianteService {

  constructor() { }

  listar():string[] {
    return ["neder", "alfonso", "fandiño", "andrade"];
  }

}

app / student / student.component.ts

import { Component /* [, mas elementos...] */} from '@angular/core';
import { EstudianteService } from '../estudiante.service';

@Component({
  selector: 'app-estudiante',
  templateUrl: './estudiante.component.html',
  styleUrls: ['./estudiante.component.css'],
  providers: [EstudianteService]
})
export class EstudianteComponent implements OnInit {

  lista:string[];
  /* Definiciones... */

  constructor(estudiante: EstudianteService) { 
    this.lista = estudiante.listar();
  }
  /* mas implementación... */

}

I am getting the following error in the console, I have not been able to determine exactly where the problem is.

I have been using angle 2 guiás based on its similar aspects and because more information abounds such as:

• link
• link

They could advise me a little with this, the truth I am studying from today I have seemed very Bacano all the subject of "divide and conquer" for this version but I got stuck at this point.

I tried to indicate the scope of the method as public

public listar():string[] {
   return ["neder", "alfonso", "fandiño", "andrade"];
}

Or at the time of calling, I have even used the term this to resemble the examples proposed in the pages of differentiated above, although I'm almost sure that has nothing to do

constructor(public estudiante: EstudianteService) { 
  this.lista = this.estudiante.listar();
}

I already appreciate the collaboration offered.