Final answer:
The question lacks explicit data to provide an exact answer for the percentage of students scoring between 50 and 70; however, percentiles and statistical analysis concepts are relevant to approximate an answer.
Step-by-step explanation:
The question does not provide specific data to calculate the exact percentage of students who scored between 50 and 70 points on the exam. Instead, relevant information about percentiles and scoring must be interpreted to provide a possible answer to the question.
When dealing with exam scores and percentiles, a percentile indicates the value below which a given percentage of observations falls. For instance, if the 90th percentile is 69.4, it denotes that 90 percent of scores are at or below 69.4 points.
The question also mentions confidence levels and population mean scores. This context suggests that the student likely encounters this question as part of a statistics problem or a discussion on statistical analysis methods such as estimating population parameters and interpreting percentiles.