Number 1 and number 3 are the same because if you are purchasing three tires that is 75% off the tires you need and one of them you get free. the free one becomes the overall discount of 25% off. number 3 is the same, the one quarter represents 25% off of the purchase.
It would be 1,200 because you just have to multiply 400 times 3 hope it helped :)
Answer:
The IQR is given by:

If we want to find any possible outliers we can use the following formulas for the limits:


And if we find the lower limt we got:


So then the left boundary for this case would be 3 days
Step-by-step explanation:
For this case we have the following 5 number summary from the data of 144 values:
Minimum: 9 days
Q1: 18 days
Median: 21 days
Q3: 28 days
Maximum: 56 days
The IQR is given by:

If we want to find any possible outliers we can use the following formulas for the limits:


And if we find the lower limt we got:


So then the left boundary for this case would be 3 days