题目

阅读下面材料，根据其内容和所给段落开头语续写两段，使之构成一篇完整的短文。续写的词数应为150左右。Have you ever had to overcome anextreme challenge in your life?My teenage years had been insane. Fromschoolwork to athletics, I had always been running around. Everything was sodifficult. Throughout my hectic teenage years Ihave been faced with many extreme challenges that have required extreme focusand hard work to overcome. If it hadn't been for hard work, none of thesechallenges that I faced would have been conquered. Two years ago, when I was a fre14．一手机厂生产A，B，C三种型号的手机，每种型号的手机均有低配版和高配版两种版本，某季度的产量如表（单位：万部）：型号A型号B型号C高配性1020z低配型305060按型号用分层抽样的方法在这个季度生产的手机中抽取40部检验，其中有A型号手机8部．（1）求z的值；（2）用分层抽样的方法在C型号的手机中抽取一个容量为6的样本，从这6个样本中任取2部手机，求至少有1部高配版手机的概率；（3）用随机抽样的方法从B型号的手机中抽取8部，经检验它们的得分如下：9.4，8.6，9.2，9.6，8.7，9.3，9.0，8.2．从这8个数中任取一个数，求该数与样本平均数之差的绝对值不超过0.5的概率．