老师帮我看看还能精简不？
<style>
body{text-align:center;padding: 100px 0;color:#f80;font-weight: 700;line-height: 2em;}
</style>
<script type="text/javascript">
var myDate = new Date();
var myxq=["星期日","星期一","星期二","星期三","星期四","星期五","星期六"];
document.write(myDate.toLocaleDateString()+myxq[myDate.getDay()]+'<br\>');
var sorceStr = "小明明:87;小花四个字:81;小一个字:97;天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76;小明明:87;小花四个字:81;小一个字:97;天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:76;小明明:87;小花四个字:81;小一个字:97;天:76;小张:74;小小:94;小西:90;小伍:76;小迪:64;小曼:96";
var myarr1=sorceStr.split(';');
var num=0;
for(i=0;i<myarr1.length;i++){
var start=myarr1[i].indexOf(':')+1;
document.write('<br\>'+'【'+myarr1[i].substring(0,start-1)+'】'+'的成绩是从第'+start+'位开始提取！');
myarr1[i]=parseInt(myarr1[i].substring(start));
num= num+=myarr1[i];
}
num=(parseInt(num)/myarr1.length).toFixed(1);
document.write('<br\>'+'总分是:'+(num*myarr1.length).toFixed(1)+'<br\>'+'平均分是：'+num+'<br\>');
</script>
