我如何过滤一个json并获得在js中创建折线图的均值？

const jsonData = '{"data":[{"x":1,"y":10},{"x":2,"y":15},{"x":3,"y":12},{"x":4,"y":18}]}';
const data = JSON.parse(jsonData).data;

const filteredData = data.filter(item => item.y > 10);

const sum = filteredData.reduce((total, item) => total + item.y, 0);
const average = sum / filteredData.length;

const canvas = document.getElementById('myChart');
const ctx = canvas.getContext('2d');

const labels = filteredData.map(item => item.x);
const values = filteredData.map(item => item.y);

new Chart(ctx, {
  type: 'line',
  data: {
    labels: labels,
    datasets: [{
      label: 'Data',
      data: values,
      fill: false,
      borderColor: 'blue',
      tension: 0.1
    }]
  }
});