Adding an image, Build a simple android app ERROR NEED HELP!

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:background="@android:color/black"
    tools:context="com.example.crystalball.MainActivity$PlaceholderFragment" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scaleType="fitCenter"
        android:src="@drawable/ball01" />

    <Button
        android:id="@+id/button1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:text="Enlighten Me"
        android:textColor="#3F0F7F"
        android:textSize="24sp"
        android:textStyle="bold|italic"
        android:typeface="serif" />

    <TextView
            android:id="@+id/textView1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center_horizontal"
            android:layout_centerVertical="true"
            android:shadowColor="@android:color/white"
            android:shadowRadius="10"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:textColor="#3f0f7f"
            android:textSize="32sp" />

</RelativeLayout>

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen" >
    <activity
        android:name="com.example.crystalball.MainActivity"
        android:label="@string/app_name" android:screenOrientation="portrait">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

styles.xml

```<resources>

    <!--
        Base application theme, dependent on API level. This theme is replaced
        by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
    -->
    <style name="AppBaseTheme" parent="Theme.AppCompat.Light">
        <!--
            Theme customizations available in newer API levels can go in
            res/values-vXX/styles.xml, while customizations related to
            backward-compatibility can go here.
        -->
    </style>

    <!-- Application theme. -->
    <style name="AppTheme" parent="AppBaseTheme">
        <!-- All customizations that are NOT specific to a particular API-level can go here. -->
         <item name="android:windowNoTitle">true</item> <!-- Hides the Action Bar -->
         <item name="android:windowFullscreen">true</item> <!-- Hides the status bar -->
    </style>

</resources>```

Crystalball.java

```package com.example.crystalball;

import java.util.Random;

public class CrystalBall {
    // Member variable (properties about the object)
    public String[] mAnswers = {
            "It is certain",
            "It is decidedly so",
            "All signs say YES",
            "The stars are not aligned",
            "My reply is no",
            "It is doubtful",
            "Better not tell you now",
            "Concentrate and ask again",
            "Unable to answer now",
            "It is hard to say" };

    // Methods (abilities: things the object can do)
    public String getAnAnswer() {

        String answer = "";

        // Randomly select one of three answers: Yes, No, or Maybe
        Random randomGenerator = new Random();
        int randomNumber = randomGenerator.nextInt(mAnswers.length);

        answer = mAnswers[randomNumber];

        return answer;
    }
}

package com.example.crystalball;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {
    private CrystalBall mCrystalBall = new CrystalBall();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Declare our View variables here
        final TextView answerLabel = (TextView) findViewById(R.id.textView1);
        Button getAnswerButton = (Button) findViewById(R.id.button1);

        getAnswerButton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                String answer = mCrystalBall.getAnAnswer();
                // Update the label with our dynamic answer
                answerLabel.setText(answer);
            }
        });

        }

    @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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }


}