fragment_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity$PlaceholderFragment"
    android:background="#0080ff">

    <ListView android:id="@+id/listview_forecast"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</FrameLayout>

MainActivity.java

package com.example.android.sunshine.app;

import android.support.v7.app.ActionBarActivity;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;


public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment())
                    .commit();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        ArrayAdapter<String> mForecastAdapter;

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {

           // just a quick framework for loading this data dynamically
           /* String day = "";
            String skies = "";
            int high = 0;
            int low = 0; */

            String [] forecastArray = {
                    /* String.format("%s — %s - %d/%d", day, skies, high, low); */
                    "Today - sunny - 56/30",
                    "Tomorrow - rainy - 64/38",
                    "Weds - cloudy - 52/32",
                    "Thur - sunny - 45/25"
                    "Fri - part. cloudy - 40/25"
                    "Sat",
                    "Sun etc"
            }; /* 5 days, prev and next */

            List<String> weekForecast = new ArrayList<String>(
                    Arrays.asList(forecastArray)
            );

            mForecastAdapter =
                new ArrayAdapter<String> (
                        getActivity(), // current context
                        R.layout.list_item_forecast, // id of list item in layout
                        R.id.list_item_forecase_textview, // id of textview to populate
                        weekForecast); // forecast data above

            View rootView = inflater.inflate(R.layout.fragment_main, container, false);

            ListView lv = (ListView) rootView.findViewById(R.id.listview_forecast);
            lv.setAdapter(mForecastAdapter);

            return rootView;
            //return inflater.inflate(R.layout.fragment_main, container, false);// — tried this based on another student's work who was also trying to get it to work
        }
    }
}