Is my tachometer too high?

So recently I have been noticing that it takes a higher tachometer reading for my car to drive. I just got the fuel injectors cleaned/replaced at sears autocenter, and the acceleration seems better. However, my car takes about 2900 rpms to drive 65-75 on the highway, and that just seems too high, at least higher than it was. Is this an issue? How much does it affect fuel consumption? How do I go about fixing this issue? For reference, I drive a 2005 Ford Focus with 49,000 miles on it.

A garage can temporarily wire-up a second tack & you can compare the two… And tacks HAVE to be programmed to the number of cylinders you have, a place for a possible problem…

If the RPMs is higher then it used to be, you may have the torque converter not locking up. It may be a bad solenoid in the transmission. Another possibility is the clutch plates in the transmission slipping (this usually doesn't happen until the mileage is a lot higher). It might be good to have the oil & filter changed in the transmission (do not let them do a high power flush… This can damage some cars). This will effect your mileage a little bit.

Can you feel your 4th gear - overdrive - engaging? The overdrive ratio on that transmission is .73 = so at the speeds you cite, the engine should be turning about 2100 rpm (your 2900 times .73).

Those transmissions were used in Fords and Mazdas for many years and are not known to be troublesome… Hopefully something simple like a shift solenoid. Ford dealer or transmission shop to diagnose.

No
that is about average

You already wasted a ton of money at Sears. No motor needs the fuel injectors cleaned or replaced at 49,000 miles!
The torque converter may not be locking up properly. Go to the dealer!

To know if the RPM's are too high requires some math. Such as finding out how many revolutions the tires need to go a mile, the differential drive ratio and the gear ratio of the transmission being used.
Most cars have a gear which is considered "direct drive" (1:1) but the differential can be such that the rear tires make fewer turns then the drive shaft does.
I honestly don't think the RPM's are out of range. Now for my SHO with a 5 speed and if I was in fifth gear they would be high. But if I was in fourth gear they would be still be high. If I was in third gear that would be about right. For the wife's Focus it is right on. The SHO can do 120 in third by the way and has a lot bigger OD tires.
FYI Focus tires have to turn 859 turns per mile. The Diff ratio is 3.83 to 1 and top gear is 0.80 for a five speed manual.

If it is higher that it used to be, Sears $%^&*( up something or something in the transmission broke.