The raw scores of 20 students of Lessened secondary school who took part in an examination in Economics are given below. The pass mark is 40%. 38 28 70 43 39 20 64 66 12 46 52 53 20 34 48 69 18 20 64 34. a) What is the mean score of the student's mark? b) How many students passed the examination? c) What percentage of the student's failed the examination?

The raw scores of 20 students are:
38, 28, 70, 43, 39, 20, 64, 66, 12, 46, 52, 53, 20, 34, 48, 69, 18, 20, 64, 34.
The number of students is $n = 20$.
The sum of the scores is:

$$\sum x = 38+28+70+43+39+20+64+66+12+46+52+53+20+34+48+69+18+20+64+34 = 838$$

The mean score ($\bar{x}$) is:

$$\bar{x} = \frac{\sum x}{n} = \frac{838}{20} = 41.9$$

a) The mean score of the student's mark is $\boxed{\text{41.9}}$.

The pass mark is 40%. Students who scored 40 or above passed.
The scores $\ge 40$ are: 70, 43, 64, 66, 46, 52, 53, 48, 69, 64.
There are 10 students who passed.

b) The number of students who passed the examination is $\boxed{\text{10}}$.

Students who scored below 40 failed.
The scores $< 40$ are: 38, 28, 39, 20, 12, 20, 34, 18, 20, 34.
There are 10 students who failed.
The percentage of students who failed is:

$$\frac{\text{Number of failed students}}{\text{Total number of students}} \times 100\% = \frac{10}{20} \times 100\% = 50\%$$

c) The percentage of students who failed the examination is $\boxed{\text{50\%}}$.

The mean score is 41.9.
The scores below 41.9 are: 38, 28, 39, 20, 12, 20, 34, 18, 20, 34.
There are 10 students who scored below the mean score.

d) The number of students who scored below the mean score is $\boxed{\text{10}}$.

First, identify the minimum and maximum scores.
Minimum score = 12.
Maximum score = 70.
The range is the difference between the maximum and minimum scores:

$$\text{Range} = \text{Maximum score} - \text{Minimum score} = 70 - 12 = 58$$

e) The range of the scores is $\boxed{\text{58}}$.

---

Question 2:

a) State five roles OPEC plays in the production, refining, and marketing of petroleum in member nations.

1. Coordinating Petroleum Policies: OPEC coordinates and unifies the petroleum policies of its member countries to secure fair and stable prices for petroleum producers.
2. Stabilizing Oil Markets: It works to stabilize international oil markets to ensure an efficient, economic, and regular supply of petroleum to consuming nations.
3. Ensuring Fair Returns: OPEC aims to ensure a steady income for oil-producing countries and a fair return on capital for those investing in the petroleum industry.
4. Influencing Production Levels: Through collective agreements on production quotas, OPEC influences global oil supply and, consequently, international oil prices.
5. Promoting Sustainable Development: It promotes sustainable development and environmental protection in the oil industry within its member states.

b) Enumerate five problems facing the organization.

1. Internal Disagreements: Member countries often have differing economic interests and political agendas, leading to difficulties in reaching consensus on production quotas and pricing strategies.
2. Competition from Non-OPEC Producers: The rise of non-OPEC oil producers (e.g., shale oil from the US) has reduced OPEC's market share and influence.
3. Global Economic Slowdowns: Economic recessions or slowdowns in major consuming nations can significantly reduce global oil demand, putting downward pressure on prices.
4. Geopolitical Tensions: Conflicts and political instability in key member states can disrupt oil supply, create uncertainty, and strain relations within the organization. 5