I\'m trying to align LinearLayout\'s vertical center which shows following pic (skycolor border) to delete button\'s vertical center.
so I set the gravity of id:grou
Change orientation and gravity in
<LinearLayout
    android:id="@+id/groupNumbers"
    android:orientation="horizontal"
    android:gravity="center_vertical"
    android:layout_weight="0.7"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">
to
android:orientation="vertical"
android:layout_gravity="center_vertical"
You are adding orientation: horizontal, so the layout will contain all elements in single horizontal line. Which won't allow you to get the element in center.
Hope this helps.
Use android:weightSum property to the parent LinearLayout and give value 3. Then in the children LinearLayout use android:layout_weight 2 and 1 respectively. Then in the First Chil LinearLayout use android:layout_gravity="center_vertical". As shown in the following code
<LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:weightSum="3"
                    android:orientation="horizontal">
                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_weight="2"
                        android:layout_gravity="center_vertical"
                        android:orientation="horizontal">
                        <TextView
                            android:id="@+id/status_text"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="00"
                            android:textColor="@color/red"
                            android:textSize="@dimen/default_text_size"
                            />
                          <TextView
                            android:id="@+id/status_text"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="00"
                            android:textColor="@color/red"
                            android:textSize="@dimen/default_text_size"
                            />
                    </LinearLayout>
                    <LinearLayout
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_weight="1">
                        <Button
                          android:layout_width="fill_parent"
                          android:layout_height="wrap_content"
                          android:text="Delete"/>
                    </LinearLayout>
                </LinearLayout>