The length of similar components produced by a company are approximated by a normal distribution model with a mean of 8 cm and a standard deviation of 0.04 cm . Let the random variable X represent the length of one component chosen at random. Accurate to 4 decimal places, the upper cutoff of the middle \( 13 \% \) has value: 8.0066 8.0033 7.9934 8 7.9967 Note: Round each of your z-scores to 3 decimal places.
Upstudy AI Solution
Answer
Solution
Answered by UpStudy AI and reviewed by a Professional Tutor


The Deep Dive
To find the upper cutoff of the middle 13% of a normal distribution, we first need to determine the z-scores that correspond to the cumulative probability of the lower 13% and the upper 13%. Since we want the middle 13%, we essentially need to find the z-scores for the cumulative probabilities of 0.435 (which is 0.5 - 0.065 for the lower side) and 0.565 (which is 0.5 + 0.065 for the upper side). Using a z-table or calculator, we find the z-scores: - For P(Z < z) = 0.435, z ≈ -0.174 - For P(Z < z) = 0.565, z ≈ 0.174 Now, we convert the upper z-score back to the raw score using the formula: \[ X = \mu + z \cdot \sigma \] Where: - μ = 8 cm (mean) - σ = 0.04 cm (standard deviation) Calculating the upper cutoff: \[ X = 8 + (0.174)(0.04) = 8 + 0.00696 = 8.00696 \] Therefore, rounding to four decimal places: The upper cutoff is **8.0070**. Among the options given, the option closest to this value is **8.0066**.