Problem Analysis #25

Kimi K3 · Run 1

Correct
16.61s
702 toks

API · no tools. This is the prompt and response recorded for this attempt; a full solution may not have been returned.

Problem Statement

This is a Korean CSAT mathematics multiple-choice problem. Solve it and put only the correct choice symbol, one of ①, ②, ③, ④, ⑤, inside \boxed{}.

Problem 26 A population is normally distributed with meanmand standard deviation 5. From this population, a random sample of size 36 is taken, and a 99% confidence interval for the population meanmis constructed using the sample mean. The resulting confidence in- terval is 1.2≤m≤a. Find the value ofa. (Here,Zdenotes a standard normal random variable, and use P(|Z| ≤2.58) = 0.99.) [3 points] ①5.1 ②5.2 ③5.3 ④5.4 ⑤5.5

Ground Truth
Recorded model response / solution
Reasoning Process

The standard error is 536=56\frac{5}{\sqrt{36}}=\frac{5}{6}.

For a 99% confidence interval, the margin of error is

2.5856=2.15.2.58\cdot \frac{5}{6}=2.15.

So the interval width is 2(2.15)=4.32(2.15)=4.3. Given the lower bound 1.21.2,

a1.2=4.3    a=5.5.a-1.2=4.3 \implies a=5.5.

\boxed{⑤}

Final Model Output

Comparative Analysis (P25) (Average across runs)

Averages use reported measurements only. Missing usage is not treated as zero.

Avg Time Taken

Motif 3
15.3
Kimi K3
12.1
Solar Pro 4
8.9
K-EXAONE-2
1.0

Avg Token Usage

Solar Pro 4
823.7
Kimi K3
756.7
K-EXAONE-2
504.7
    CSAT 2026 · Problem 25 · Kimi K3 | EntropyMath