Official Solution: Bunuel
Eight food trucks operated during a week-long downtown festival. The table shows each truck’s meals served, average (arithmetic mean) preparation time per order (in minutes), on-time rate (percentage of orders ready by the promised time), and the number of customer complaints recorded that week.
| Truck | Meals served | Avg prep time (min) | On-time rate (%) | Complaints |
| KokoBowl | 720 | 9.4 | 89 | 9 |
| SmokySpud | 860 | 11.2 | 85 | 14 |
| GreenWrap | 910 | 8.6 | 92 | 7 |
| TacosAlto | 980 | 9.0 | 90 | 8 |
| NoodleNest | 640 | 12.4 | 83 | 16 |
| CurryDash | 1050 | 9.4 | 88 | 10 |
| Buns and Pickles | 780 | 9.4 | 86 | 13 |
| PokePort | 940 | 8.9 | 93 | 6 |
For each statement, select
Yes if the statement is true based on the table; otherwise, select
No.
• If all trucks with on-time rates below 86% are excluded, the average prep time of the remaining trucks is lower than the overall average prep time of all eight trucks. The only trucks below 86% are SmokySpud (85%) and NoodleNest (83%), whose prep times are 11.2 and 12.4 minutes, the two highest in the dataset. Removing values above the mean pulls the mean downward, so the remaining mean prep time is lower.
Answer:
Yes • Among the four parameters shown, the number of complaints has the lowest standard deviation. Standard deviation measures how spread out the values are from the mean. Looking at the complaints column, the values range from 6 to 16, with a mean of about 10. In comparison, the average prep times range only from 8.6 to 12.4, so the range there is roughly half as wide, and the mean is also close to 10.
Checking the values in these two columns, we can see that the variation from the mean in complaints is larger than the variation from the mean in prep times. Thus, the average prep time must have a smaller standard deviation compared to complaints.
Answer:
No • More trucks are simultaneously above the median in meals served and below the median in prep time than are simultaneously below the median in meals served and above the median in prep time. Meals median is the average of 860 and 910, which is 885. Prep-time median is the average of 9.4 and 9.4, which is 9.4. Above-meals-and-below-prep group: GreenWrap, TacosAlto, PokePort (3). Below-meals-and-above-prep group: SmokySpud and NoodleNest (2). Since 3 is greater than 2, the claim holds.
Answer:
Yes Correct answer: If all trucks with on-time rates below 86% are excluded, the average prep time of the remaining trucks is lower than the overall average prep time of all eight trucks.
"Yes"Among the four parameters shown, the number of complaints has the lowest standard deviation.
"No"More trucks are simultaneously above the median in meals served and below the median in prep time than are simultaneously below the median in meals served and above the median in prep time.
"Yes"