Answer:
Between 21 years and 75 years
Step-by-step explanation:
Given that a real estate company is interested in the ages of home buyers. They examined the ages of thousands of home buyers and found that the mean age was 48 years old, with a standard deviation of 9 years.
X the ages of home buyers is N(48, 9)
a) 
Hence using Cheby chev inequality

b) 

c) Using normal distribution we have

d) z value is 2.97
Hence x lies between

Between 21 years and 75 years
“Three decimal places” is the same as “the nearest thousandth.” So, for example, if you are asked to round 3.264 to two decimal places it means the same as if your are asked to round 3.264 to the nearest hundredth. Some questions, like the example below, will ask you to “show your answer correct to two decimal places."
La pregunta está incompleta ya que no se da el costo de la colocación de baldosas por m².
Suponga que el costo de los mosaicos por m² = c
Respuesta:
39.06c
Explicación paso a paso:
El costo del embaldosado será:
El costo por m² * área total a embaldosar
Dado que :
La dimensión de la habitación a embaldosar es:
Longitud = 9,30 metros
Ancho = 4.20 metros
El área total de la habitación a embaldosar es = Largo * ancho
Área total de la habitación a embaldosar = 9,30 m * 4,20 m
Superficie total de la habitación a embaldosar = 39,06 m²
Si el costo del mosaico por m² = c
El costo de embaldosar la habitación será:
39,06 * c = 39,06c
Answer:<u>0.8, just add up and find the mean</u>