Essential Studio for Xamarin.Forms
Combination Chart / Mixed Chart

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:local="clr-namespace:ChartExample"
             xmlns:chart="clr-namespace:Syncfusion.SfChart.XForms;assembly=Syncfusion.SfChart.XForms"
             x:Class="ChartExample.MainPage">
    
    <ContentPage.BindingContext>
        <local:ViewModel/>
    </ContentPage.BindingContext>
	
	<chart:SfChart>
			
		<chart:SfChart.PrimaryAxis>
			<chart:CategoryAxis/>
		</chart:SfChart.PrimaryAxis>

		<chart:SfChart.SecondaryAxis>
			<chart:NumericalAxis/>
		</chart:SfChart.SecondaryAxis>

		<chart:AreaSeries ItemsSource="{Binding AreaData}" XBindingPath="Month" YBindingPath="Target"/>

		<chart:ColumnSeries ItemsSource="{Binding ColumnData}" XBindingPath="Month" YBindingPath="Target"/>

	</chart:SfChart>
	
</ContentPage>

public class Model
{
    public string Month { get; set; }

    public double Target { get; set; }

    public Model(string xValue, double yValue)
    {
        Month = xValue;
        Target = yValue;
    }
}

public class ViewModel
{
    public ObservableCollection<Model> AreaData { get; set; }
    
    public ObservableCollection<Model> ColumnData { get; set; }
    
    public ViewModel()
    {
        AreaData = new ObservableCollection<Model>()
        {
            new Model("Jan", 50),
            new Model("Feb", 70),
            new Model("Mar", 65),
            new Model("Apr", 57),
            new Model("May", 48), 
        };

        ColumnData = new ObservableCollection<Model>()
        {
            new Model("Jan", 20),
            new Model("Feb", 30),
            new Model("Mar", 25),
            new Model("Apr", 47),
            new Model("May", 38), 
        };
    }
}