استفسارات , اسئله , مساعده .. احصاء .. دوري 1

[رسووله]

12. A researcher wishes to represent the percentage of students in the department of statistics using a
pie graph. If the percentage of statistical department students is 25%, then their corresponding
degree of the angle on the pie graph is .........

A) 300
B) 1080
C) 900
D) 1800

>>> هنا بالنظر نعرف .. نقول الـ 100% ربعها 25%
والدائره اذا قسمناها ارباع كل ربع بيكون زاويته 90 درجه




The range of the data set -3, -7, -13, 0, -1 is .........

A) -13
B) 13
C) 2
D) 12


>>> R=H-L=0-(-13)=13




21. If a sample of data has mean 25 and variance 25, then its coefficient of variation is .........

A) 1%
B) 0.2%
C) 20%
D) 100%


>>> من قاعدة coefficient variation .. واحنا عارفين اننا نحتاج ستاندرد ديفييشن اللي هي جذر الفارينس




28. Calculate the standard deviation for this sample:

2, 5, 3, 5, 4

A) 4.3
B) 18.8
C) 1.7
D) 1.3


>>> من قاعدة standard deviation
مجموع X = 19 .. وطبعا هو يبيها بالتربيع يعني = 316
مجموع X تربيع = 79
n=5



41. A student scored 82 on an Arabic exam that had a mean of 88 and a standard deviation of 6; he
scored 58 on a Mathematics exam with a mean of 60 and a standard deviation of 5. Which of these
exam scores has a better position?

A) Mathematics exam is better
B) No difference between both exams
C) Arabic exam is better
D) None of the above


>>> من قاعدة Z score ..
في العربي بيطلع -1
وفي الماث -.4
وطبعا واضح الدرجه الافضل في الماث