Identify q¹,q²,q³ and the iqr of the data: 50,65,70,120,130,145,70,55,45

Q₁=Middle of the median and the first number in an ordered set from least to greatest.

Q₂=Median

Q₃=Middle of the median and the last number in an ordered set from least to greatest.

Order numbers from least to greatest:

45, 50, 55, 65, 70, 70, 120, 130, 145

Now, find the middle of the data set, which is the first 70 in the data set.

Now, from there, find the middle of the first half of the set.

First half: 45, 50, 55, 65

Q₁=52.5 because it is half of 50 and 55.

Second half: 70, 120, 130, 145

Q₃=125 because it is half of 120 and 130.

So your answer is:
 
Q₁=52.5

Q₂=70

Q₃=125

~Hope I helped!~