Building a is 262262 meters taller than building b. if the height of building a is subtracted from twice the height of building b, the result is 229229 meters. how tall is each skyscraper?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?