A- is my guess.

I would also say A-
Let’s say that a B is 80%, (B+ is 80–84%), A- is 85(-89)%, A is 90%.
You got 90+90+80+85=345
345/4=86.25 which looking at my initial parametres is probably an A-.

You need to provide a little more information. Do they calculate grades by your actual percentile, or do they use the letter grade and assign points? It should make no difference if the A is an A- or just an A.

A=4 B=3 C=2 D=1
3(4) + 3= 15 points, divided by 4 semesters = 3–¾, or 3.75, which would be a B

@BarnacleBill Her lowest grade was a B. How could the average be the same as the lowest?

Because if you use a point system, which is what they do in college, that B will wreck your A. Some schools weight +s and -s, others do not. If a 4 is an A, then one B will cause your average to not be a 4.

The OP has not provided enough information about how her school calculates grades. There is several methods.

The average comes to an A-, as others have said.
@BarnacleBill , If there were 10 A’s and a B, by your reckoning that would work out to a B, because the average would be less than 4. That can’t be right.

@BarnacleBill You are ignoring the possibility of + and – grades. If a 4 is an A, then an A- must be somewhere between a 3 and a 4. Running the numbers through the three different grading systems I have learned, I get an A- on each one. If final grades must be flat grades (i.e., if they cannot have a + or – attached), then typically one takes the “level” of the earned grade as the final grade. So an A+, A, and A- would all become an A since they are all A-level grades, a B+, B, and B- would all become a B since they are all B-level grades, and so forth. Almost no one insists on all final grades being flat grades, though.

@LostInParadise (43 / 11) = 3.9090… which is less than 4, and some places won’t round up.
@SavoirFaire ”Almost no one” =/= “no one”. I’ve seen enough strange things to think that normal no longer exists :p

Without knowing how they grade, it’s impossible to say, but if we assume they are fairly normal, I would say A- or, if they are only slightly screwy, an AB.

@jerv Well, of course. That’s why I included the word “almost.” And since normal is a statistical concept, there must be some range of grading practices that can be called normal. Regardless, my point was that even if @kittykat219‘s school uses flat grades, the final grade in this case still wouldn’t be a B.

@LostInParadise, eventually you will reach a point where you round up the number to an A. Admittedly, 3.75 should round up to an A, since the rule for rounding is .5 and over is that it rounds up to the next whole number.

@SavoirFaire, some schools do assign fractional weights to + and – grades on a 4 point scale, and some schools weight AB and AP classes on on a 5 point scale, so that an A in an AB/AP class is worth 5 points, rather than 4 points. Which is why I stated that I thought the OP did not provide enough information to answer her question.

between an A and an A-