سؤالين في الأحصاء

[sultanooh]

السلام عليكم

من ثر المراجعه ضيعت طريقة الحل لهذه الأسئلة

امس حليتها والحين ماني عارفلها

حلوها سريع مع الطريقة

The scores of a college entrance test is normally distributed with mean 450 and a standard deviation 50.

Answer the following five questions

If a sample of 36 students is selected, find the probability that the mean scores of the sample is
below 465.

A) 0.7881 B) 0.9332 C) 0.9641 D) 0.8849

32.

Find the percentage of students who scored between 485 and 590.

A) 58.20% B) 46.42% C) 68.53% D) 23.94%