A study of residents in the city of Houston showed that the…

A study of residents in the city of Houston showed that the mean income for all adults is $75,000 with a standard deviation of $5,000.  A randomly selected sample of these residents showed an average income of $78,000 with a standard deviation of $4,700. Are the numbers $78,000 and $4,700 statistics or parameters? Explain.

A school district’s study 5 years ago showed that the averag…

A school district’s study 5 years ago showed that the average number of special education students per grade was 12 students.   Now, the school district is considering increasing the number of special education teachers because they believe the average number of special education students per grade has significantly increased.  After running a hypothesis test, the result was reject Ho and accept Ha.  What decision should the school district make regarding increasing the number of special education teachers?