There are 27 children in the class.
18 divided by two equals 9
9 times 3 is 27
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:
Answer:
18.7 years
Step-by-step explanation:
This is a compound interest problem and the following variables have been given;
Principal = 4000; this is the amount o be invested
APR = 9%; this is the compound interest to be earned
Accumulated amount = 20,000
We are required to determine the duration in years. We apply the compound interest formula;
The next step is to introduce natural logarithms in order to determine n;
The number of years required is thus 18.7 years
41.848/3.4=12.308
The actual building is 12.306 times larger than the model.
Answer:
-50
Step-by-step explanation:
