Answer:
Mrs. Stern washed more
laundry still needs to be washed.
Step-by-step explanation:
Total amount of laundry: 


of the laundry still needs to be done.
Mrs. Stern washed
of the laundry.
Her son washed
of the laundry.
Mrs. Stern washed more laundry than her son.
Answer:
The test statistic is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is 
The sample mean is 
The standard deviation is 
Generally the test statistics is mathematically represented as

substituting values


The equation is true 20/-10=-12/6 or -2=-2