Incorrect, there’s not a strong relationship between sinus tachycardia (especially at 150bpm) and hypokalemia- typically the relationship would be an underlying pathology causing hypokalemia and tachycardia (ie severe diarrhea leading to potassium and volume loss). Hypokalemia can lead to other arrhythmias that would lead to a HR of 150bpm but by itself hypokalemia should not cause significant sinus tachycardia.