Mean & Std Dev for Norm Dist. Exam Marks - 450 Stud.

In summary, the mean and standard deviation of marks scored by candidates can be found using the given information. There are 25 first class students, 90 failed students, and a total of 450 candidates.
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wajeehayas
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Assuming that the number of marks scored by a candidate is normally distributed, find the mean and the standard deviation, if the number of first class students(60% or more marks) is 25, the number of failed students(less than 30%marks) is 90 and the total number of candidates appearing for the examination is 450.
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Hello wajeehayas and welcome to MHB! :D

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Related to Mean & Std Dev for Norm Dist. Exam Marks - 450 Stud.

1. What is the mean for the exam marks of 450 students?

The mean for the exam marks of 450 students is the average score achieved by all 450 students. It is calculated by adding up all the individual scores and dividing by the total number of students (450). This gives an overall measure of the central tendency of the data.

2. How is the standard deviation calculated for this data set?

The standard deviation for the exam marks of 450 students is a measure of the spread or variability of the data. It is calculated by finding the difference between each individual score and the mean, squaring those differences, adding them up, dividing by the total number of students (450), and then taking the square root. This gives an overall measure of how much the scores deviate from the mean.

3. Why is the normal distribution used for analyzing exam marks?

The normal distribution is a commonly used distribution in statistics and is often used to model real-world data, including exam marks. It is a bell-shaped curve that is symmetrical and has a defined mean and standard deviation. This makes it a useful tool for understanding the distribution of scores and identifying any potential outliers or trends in the data.

4. Can the mean and standard deviation be used to make predictions about future exam marks?

Yes, the mean and standard deviation can be used to make predictions about future exam marks. By understanding the distribution of scores and the variability within the data, we can estimate the likelihood of certain scores occurring in future exams. However, it is important to note that there are other factors that can also impact exam scores, so these predictions may not always be accurate.

5. How can the mean and standard deviation be used to compare the performance of different groups of students?

The mean and standard deviation can be used to compare the performance of different groups of students by calculating these measures for each group and then comparing them. This can help identify any significant differences or similarities in the exam marks between the groups. However, it is important to consider any potential confounding factors that may impact the results, such as differences in study habits or prior knowledge.

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