If 81km = 9L, then 9km = 1L.
So ?km = 22L.
With 22L, Amanda can drive 198km.
Answer:
The correct answer is - an observational study.
Step-by-step explanation:
It is given that, Researchers periodically survey a few thousand of the patients. These are taking specific medicine patients and researchers taking this survey to find the connection between that medication and the subjects' general health.
So, it can say that the researchers observed the patient's health by the effect of the medication, therefore, the Observational Study is the given method of gathering data.
The probability that a two-digit number selected at random has a tens digit less than its units digit is 0.2667 (4/15).

There are 90 two-digit numbers (99-9). Of these, six numbers are divisible by 15 (15, 30, 45, 60, 75, 90). This is also divisible by 5. Therefore, the preferred case is 30-6 = 24. Therefore, the required probability is 24/90 = 4/15.
The probability of an event can be calculated by simply dividing the number of favorable results by the total number of possible results using a probabilistic expression. Whenever you are uncertain about the outcome of an event, you can talk about the probability of a particular outcome, that is, its potential.
Learn more about probability here: brainly.com/question/24756209
#SPJ4
Answer:
6.0 miles
Step-by-step explanation:
The sequence of distances is a geometric sequence with first term a1 and common ratio (1 +10%) = 1.10. The sum of 7 terms of the sequence is ...
S7 = a1·(r^7 -1)/(r -1)
56.923 = a1·(1.1^7 -1)/(1.1 -1)
5.6923 = a1·0.9487171
Dividing by the coefficient of a1 gives its value:
5.6923/0.9487171 ≈ 5.999997 ≈ 6.000
The hiker traveled 6.0 miles on the first day.