Answer:
Lowest acceptable score = 121.3
Step-by-step explanation:
Mean test score (μ) = 115
Standard deviation (σ) = 12
The z-score for any given test score 'X' is defined as:
In this situation, the organization is looking for people who scored in the upper 30% range, that is, people at or above the 70-th percentile of the normally distributed scores. At the 70-th percentile, the corresponding z-score is 0.525 (obtained from a z-score table). The minimum score, X, that would enable a candidate to apply for membership is:

Not sure if this is exactly what you want but an= a1 + (n - 1)d
For this case, what we must do is calculate the mean of the given data.
For this, we must do the following:
Add the given numbers and divide by the number of numbers.
We have then:

From here, we clear the value of x.
We have then:
Answer:
Tasha would have to score 90 on the sixth test to have a mean of 85
I think the wrong is the answer , I hope that help , good luck
Decimal: 0.015625 or as fraction= 1/64. Glade I could help!