بنات عندي اربعه اسئله ممكن حلها
اول سؤال
The average age of Amtrak passenger train cars is 19.4 years. If
the distribution of ages is normal and 20% of the cars are older
than 22.8 years, find the standard deviation.
|
توجدي او المين وهو عباره عن 42+48/ 2 = 45
وبعدين تحلي معادلة كمجهول
من خلا هدا القانون z= x-µls