Boys' scores (\%)
\begin{tabular}{|l|l|l|l|l|l|l|}
\hline
48 & 56 & 57 & 58 & 65 & 66 & 66 \\
\hline
68 & 73 & 77 & 78 & 81 & 85 & 96 \\
\hline
\end{tabular}

Girls' scores (\%)
\begin{tabular}{|l|l|l|l|l|l|l|l|l|l|l|l|l|}
\hline
38 & 11 & 75 & 5 & 49 & 9 & 79 & 4 & 39 & 10 & 99 & 1 & 56 \\
\hline
67 & 6 & 98 & 7 & 89 & 3 & 59 & 7 & 75 & 5 & 75 & & \\
\hline
\end{tabular}

1. Arrange the girls' scores in descending order.

2. Write down the girls' modal score.

3. Calculate the boys' mean score.

4. Calculate the boys' median score.

5. Determine the range of the girls' scores.

6. Determine the probability that a boy chosen at random scores 75 in the test. Write your answer in percentage form.



Answer :

Sure, let's break down each part of the question step-by-step:

### 1.1.1 Arrange the girls' scores in descending order.

To arrange the girls' scores in descending order, we start by listing the scores:
[tex]\[38, 11, 75, 5, 49, 9, 79, 4, 39, 10, 99, 1, 568, 67, 6, 98, 7, 89, 3, 59, 7, 75, 5, 75\][/tex]

Now, we sort these scores from the highest to the lowest:

[tex]\[568, 99, 98, 89, 79, 75, 75, 75, 67, 59, 49, 39, 38, 11, 10, 9, 7, 7, 6, 5, 5, 4, 3, 1\][/tex]

### 1.1.2 Write down the girls' modal score.

The modal score is the score that appears the most frequently. In the sorted list:
[tex]\[568, 99, 98, 89, 79, 75, 75, 75, 67, 59, 49, 39, 38, 11, 10, 9, 7, 7, 6, 5, 5, 4, 3, 1\][/tex]

You can see that the score 75 appears three times, which is more frequent than any other score.

Thus, the girls' modal score is [tex]\(75\)[/tex].

### 1.1.3 Calculate the boys' mean score.

To calculate the mean score, we add up all the boys' scores and then divide by the number of scores. The boys' scores are:

[tex]\[48, 56, 57, 58, 65, 66, 66, 68, 73, 77, 78, 81, 85, 96\][/tex]

First, add them up:

[tex]\[48 + 56 + 57 + 58 + 65 + 66 + 66 + 68 + 73 + 77 + 78 + 81 + 85 + 96 = 974\][/tex]

There are 14 scores, so we divide the total by 14:

[tex]\[ \text{Mean score} = \frac{974}{14} \approx 69.57 \][/tex]

So, the boys' mean score is approximately [tex]\(69.57\)[/tex].

### 1.1.4 Calculate the boys' median score.

To find the median score, we first need to sort the boys' scores in ascending order:

[tex]\[48, 56, 57, 58, 65, 66, 66, 68, 73, 77, 78, 81, 85, 96\][/tex]

There are 14 scores, so the median is the average of the 7th and 8th scores. The 7th and 8th scores are:

66 and 68

Thus, the median is:

[tex]\[ \text{Median score} = \frac{66 + 68}{2} = 67 \][/tex]

So, the boys' median score is [tex]\(67\)[/tex].

### 1.1.5 Determine the range of the girls' scores.

The range is found by subtracting the smallest score from the largest score. Looking at the sorted list:

[tex]\[568, 99, 98, 89, 79, 75, 75, 75, 67, 59, 49, 39, 38, 11, 10, 9, 7, 7, 6, 5, 5, 4, 3, 1\][/tex]

The largest score is [tex]\(568\)[/tex] and the smallest score is [tex]\(1\)[/tex]. So the range is:

[tex]\[ \text{Range} = 568 - 1 = 567 \][/tex]

Thus, the range of the girls' scores is [tex]\(567\)[/tex].

### 1.1.6 Determine the probability that a boy chosen at random scores 75 (1) in the test.

First, we note that none of the boys' scores are 75. The boys' scores are:

[tex]\[48, 56, 57, 58, 65, 66, 66, 68, 73, 77, 78, 81, 85, 96\][/tex]

No score of 75 is present.

The total number of boys is 14, and the number of boys scoring 75 is 0. The probability is:

[tex]\[ \text{Probability} = \frac{\text{Number of boys scoring 75}}{\text{Total number of boys}} \times 100\% = \frac{0}{14} \times 100\% = 0\% \][/tex]

Therefore, the probability that a randomly chosen boy scores 75 is [tex]\(0\%\)[/tex].