Answer:
9
Step-by-step explanation:
90+81+mising angle=180, missing angle is 9
Answer:
Answer for the question:
The Rockwell hardness of a metal is determined by impressing a hardened point into the surface of the metal and then measuring the depth of penetration of the point. Suppose the Rockwell hardness of a particular alloy is normally distributed with mean 69 and standard deviation 2.7.
a. If a specimen is acceptable only if its hardness is between 67 and 75, what is the probability that a randomly chosen specimen has an acceptable hardness?
b. If the acceptable range of hardness is (69-C, 69+C), for what value of C would 95% of all specimens have acceptable hardness?
c. If the acceptable range is as in part (a) and the hardness of each of ten randomly selected specimens is independently determined, what is the expected number of acceptable specimens among the ten?
d. What is the probability that at most eight of ten independently selected specimens have a hardness of less than 72.84(HINT Y=number among the ten specimens with hardness less than72.84 is a binomial variable; what is p?)
is given in the attachment.
Step-by-step explanation:
The correct value is -10.
7 plus negative 10 equals negative 3.
Negative 3 times 4 equals -12.
Or, (7+-10=-3•4=-12)
The diameter of the tank = 9 feet
So radius is = 
feet
Height of the tank = 25 feet
The top of the tank must be circular with same radius as 4.5 feet
So, to calculate the area of the tank and top, we will add the curved or lateral surface area of tank and area of circle
Curved or lateral Surface area of cylindrical area = 2*PI*r*h
= 
= 706.50 square feet
And area of the circular top = PI*r²
= 
= 63.585 square feet
So, total area that will be painted = 
= 770.085 square feet
Or rounding up to 2 decimal places = 770.09 square feet.
