diff --git a/src/features/votes/services/vote_statistics.test.ts b/src/features/votes/services/vote_statistics.test.ts
index ea3113f30..89d32000d 100644
--- a/src/features/votes/services/vote_statistics.test.ts
+++ b/src/features/votes/services/vote_statistics.test.ts
@@ -4,6 +4,7 @@ import { TaskGrade } from '@prisma/client';
 
 import {
   getVoteGradeStatistics,
+  getVoteGradeStatisticsForTaskIds,
   getAllTasksWithVoteInfo,
   getVoteCountersByTaskId,
   getVoteStatsByTaskId,
@@ -290,3 +291,52 @@ describe('getAllVoteCounters', () => {
     expect(prisma.votedGradeCounter.findMany).toHaveBeenCalledWith();
   });
 });
+
+describe('getVoteGradeStatisticsForTaskIds', () => {
+  test('returns an empty Map without querying the DB when taskIds is empty', async () => {
+    const result = await getVoteGradeStatisticsForTaskIds([]);
+
+    expect(result.size).toBe(0);
+    expect(prisma.votedGradeStatistics.findMany).not.toHaveBeenCalled();
+  });
+
+  test('queries with a WHERE IN filter for the given taskIds', async () => {
+    mockVotedGradeStatisticsFindMany([]);
+
+    await getVoteGradeStatisticsForTaskIds(['abc001_a', 'abc002_a']);
+
+    expect(prisma.votedGradeStatistics.findMany).toHaveBeenCalledWith({
+      where: { taskId: { in: ['abc001_a', 'abc002_a'] } },
+    });
+  });
+
+  test('returns an empty Map when no matching statistics exist', async () => {
+    mockVotedGradeStatisticsFindMany([]);
+
+    const result = await getVoteGradeStatisticsForTaskIds(['abc001_a']);
+
+    expect(result.size).toBe(0);
+  });
+
+  test('maps each taskId to its statistics record', async () => {
+    const stat = makeStatisticsRecord({ taskId: 'abc001_a', grade: TaskGrade.Q5 });
+    mockVotedGradeStatisticsFindMany([stat]);
+
+    const result = await getVoteGradeStatisticsForTaskIds(['abc001_a']);
+
+    expect(result.get('abc001_a')?.grade).toBe(TaskGrade.Q5);
+  });
+
+  test('returns only statistics for the specified taskIds', async () => {
+    const records = [
+      makeStatisticsRecord({ taskId: 'abc001_a', grade: TaskGrade.Q5 }),
+      makeStatisticsRecord({ id: 'stats-abc002_a', taskId: 'abc002_a', grade: TaskGrade.D1 }),
+    ];
+    mockVotedGradeStatisticsFindMany(records);
+
+    const result = await getVoteGradeStatisticsForTaskIds(['abc001_a', 'abc002_a']);
+
+    expect(result.size).toBe(2);
+    expect(result.get('abc002_a')?.grade).toBe(TaskGrade.D1);
+  });
+});
diff --git a/src/features/votes/services/vote_statistics.ts b/src/features/votes/services/vote_statistics.ts
index 9149fc664..e84483c50 100644
--- a/src/features/votes/services/vote_statistics.ts
+++ b/src/features/votes/services/vote_statistics.ts
@@ -24,6 +24,19 @@ export async function getVoteGradeStatistics(): Promise<Map<string, VotedGradeSt
   return gradesMap;
 }
 
+export async function getVoteGradeStatisticsForTaskIds(
+  taskIds: string[],
+): Promise<Map<string, VotedGradeStatistics>> {
+  if (taskIds.length === 0) {
+    return new Map();
+  }
+
+  const stats = await prisma.votedGradeStatistics.findMany({
+    where: { taskId: { in: taskIds } },
+  });
+  return new Map(stats.map((s) => [s.taskId, s]));
+}
+
 export async function getAllTasksWithVoteInfo(): Promise<TaskWithVoteInfo[]> {
   const [allTasks, stats, counters] = await Promise.all([
     prisma.task.findMany({ orderBy: { task_id: 'desc' } }),
diff --git a/src/routes/workbooks/[slug]/+page.server.ts b/src/routes/workbooks/[slug]/+page.server.ts
index 2d5ef1f40..599213f9b 100644
--- a/src/routes/workbooks/[slug]/+page.server.ts
+++ b/src/routes/workbooks/[slug]/+page.server.ts
@@ -1,11 +1,11 @@
 import { error, type Actions } from '@sveltejs/kit';
 
 import { Roles } from '$lib/types/user';
-import type { TaskResult } from '$lib/types/task';
 
 import * as taskResultsCrud from '$lib/services/task_results';
 import { getWorkbookWithAuthor } from '$features/workbooks/services/workbooks';
 import * as action from '$lib/actions/update_task_result';
+import { getVoteGradeStatisticsForTaskIds } from '$features/votes/services/vote_statistics';
 
 import { isAdmin, canRead } from '$lib/utils/authorship';
 import { getLoggedInUser } from '$features/auth/services/session';
@@ -36,16 +36,18 @@ export async function load({ locals, params, url }) {
     error(FORBIDDEN, `問題集id: ${slug} にアクセスする権限がありません。`);
   }
 
-  const taskResults: Map<string, TaskResult> = await taskResultsCrud.getTaskResultsByTaskId(
-    workBook.workBookTasks,
-    loggedInUser?.id as string,
-  );
+  const taskIds = workBook.workBookTasks.map((t) => t.taskId);
+  const [taskResults, voteStatisticsMap] = await Promise.all([
+    taskResultsCrud.getTaskResultsByTaskId(workBook.workBookTasks, loggedInUser?.id as string),
+    getVoteGradeStatisticsForTaskIds(taskIds),
+  ]);
 
   return {
     isLoggedIn: loggedInUser !== null,
     loggedInAsAdmin: loggedInAsAdmin,
     ...workbookWithAuthor,
     taskResults: taskResults,
+    voteStatisticsMap: voteStatisticsMap,
   };
 }
 
diff --git a/src/routes/workbooks/[slug]/+page.svelte b/src/routes/workbooks/[slug]/+page.svelte
index 87152b3d2..3cfbe519e 100644
--- a/src/routes/workbooks/[slug]/+page.svelte
+++ b/src/routes/workbooks/[slug]/+page.svelte
@@ -18,6 +18,7 @@
   import ExternalLinkWrapper from '$lib/components/ExternalLinkWrapper.svelte';
   import PublicationStatusLabel from '$features/workbooks/components/shared/PublicationStatusLabel.svelte';
   import CommentAndHint from '$features/workbooks/components/detail/CommentAndHint.svelte';
+  import RelativeEvaluationBadge from '$features/votes/components/RelativeEvaluationBadge.svelte';
 
   import { getBackgroundColorFrom } from '$lib/services/submission_status';
 
@@ -33,6 +34,7 @@
   let workBook = data.workBook;
   let workBookTasks: WorkBookTaskBase[] = $state([]);
   let taskResults: Map<string, TaskResult> = $derived(data.taskResults);
+  let voteStatisticsMap = $derived(data.voteStatisticsMap);
 
   let isLoggedIn = data.isLoggedIn;
 
@@ -157,6 +159,8 @@
         </TableHead>
         <TableBody class="divide-y divide-gray-200 dark:divide-gray-700">
           {#each workBookTasks as workBookTask (workBookTask.taskId)}
+            {@const taskGrade = getTaskGrade(workBookTask.taskId)}
+            {@const statsEntry = voteStatisticsMap?.get(workBookTask.taskId)}
             <TableBodyRow
               id={getUniqueIdUsing(workBookTask.taskId)}
               class={getBackgroundColorFrom(getTaskResult(workBookTask.taskId).status_name)}
@@ -164,7 +168,16 @@
               <!-- 問題のグレード -->
               <TableBodyCell class="justify-center w-16 px-0.5 xs:px-3">
                 <div class="flex items-center justify-center min-w-[54px] max-w-[54px]">
-                  <GradeLabel taskGrade={getTaskGrade(workBookTask.taskId)} />
+                  <div class="relative">
+                    <GradeLabel {taskGrade} />
+                    {#if taskGrade !== TaskGrade.PENDING && statsEntry}
+                      <RelativeEvaluationBadge
+                        officialGrade={taskGrade}
+                        medianGrade={statsEntry.grade}
+                        badgeId="rel-eval-{getUniqueIdUsing(workBookTask.taskId)}"
+                      />
+                    {/if}
+                  </div>
                 </div>
               </TableBodyCell>