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:
-3
Step-by-step explanation:
<h3>20 subtracted from three times a number is 6 more than the number. Then the number is 13</h3>
<em><u>Solution:</u></em>
<em><u>Given statement is:</u></em>
20 subtracted from three times a number is 6 more than the number
We can translate the sentence into algebraic expression
Let "a" be the unknown number
Then,
20 subtracted from three times "a" is 6 more than "a"
Which means,
3a - 20 = 6 + a
3a - a = 6 + 20
2a = 26
Divide both sides by 2
a = 13
Thus the number is 13
Answer:
Step-by-step explanation:
Arithmetic sequence
Tn = a+(n-1)d
= -85 +(601-1) 1/6
= -85 + 600/6
= -85 + 100
= 15
601th term is 15
A=h•b/2
h=2x+1
b=2x
A=(2x+1) •2x/2
Divide numerator and denominator by 2
A=x(2x+1)
