How to get value from a TextView which is in a ListView without any custom adapters?

Question

I have a ListView with a TextView (which has an integer as string) and a Seekbar. I need to extract the integer value and set it to the Seekbar.

Unfortunately, when I do this, I get a NullPointer exception because the content that populates the ListView item is not recognized by the onCreateView of the PlaceholderFragment.

String progressValue = percentileTextView.getText().toString();
bar.setProgress(Integer.parseInt(progressValue));

I have an activity layout for this activity, then a fragment layout which contains the listview and then I have a content.xml where the actual TextView is present. My question is how to reference this TextView? Am I doing this right, i.e. Activity layout contains a ConstraintLayout with Toolbars etc, then the Fragment Layout contains the ListView and I am using a separate content.xml and applying that to the ListView via a SimpleAdapter.

 newAdapter = new SimpleAdapter(getContext(), newList,
                                R.layout.content, new String[] {
                                    "name",
                                    "percent"
                                },
                                new int[] {
                                    R.id.name1, 
                                    R.id.percentile1
                                });

I hope you understand my problem.

When I do the following, it works (i.e. Android Studio understand that is the TextView) - but throws a null pointer exception upon build.

TextView percentileTextView = (TextView) rootView.findViewById(R.id.percentile1);

UPDATE 1 for pskink:

Newlist contents:

[{TA=Item1, IA=46}, {TA=Item2, IA=98}, {TA=Item3, IA=70}, {TA=Item4, IA=54}, {TA=Item5, IA=99}, {TA=Item6, IA=98}]

Row item layout (content.xml):

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="@dimen/activity_horizontal_margin">
    <TextView
        android:id="@+id/name1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:paddingBottom="2dip"
        android:textStyle="bold"
        android:textColor="@color/colorAccent" />
    <RelativeLayout
        android:layout_height="wrap_content"
        android:layout_width="fill_parent"
        android:padding="5dp">
    <TextView
        android:id="@+id/greater_than"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#5d5d5d"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:text="@string/greater_than" />
        <TextView
            android:id="@+id/percentile1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textColor="#5d5d5d"
            android:layout_toRightOf="@id/greater_than"
            android:layout_toEndOf="@id/greater_than"
            android:textStyle="bold" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#5d5d5d"
        android:layout_toRightOf="@id/percentile1"
        android:layout_toEndOf="@id/percentile1"
        android:text="@string/percentile_text"/>


    </RelativeLayout>
    <SeekBar
        android:id="@+id/seekBar2"
        android:paddingTop="12dip"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:gravity="end|bottom"
        android:paddingTop="12dip"
        android:orientation="horizontal">
        <ImageView
            android:contentDescription="info"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:src="@mipmap/someimg" />
    </LinearLayout>

</LinearLayout>