Answer:
(12.1409, 14.0591
Step-by-step explanation:
Given that Tensile strength tests were performed on two different grades of aluminum spars used in manufacturing the wing of a commercial transport aircraft. From past experience with the spar manufacturing process and the testing procedure, the standard deviations of tensile strengths are assumed to be known.
Group Group One Group Two
Mean 87.600 74.500
SD 1.000 1.500
SEM 0.316 0.433
N 10 12
The mean of Group One minus Group Two equals 13.100
standard error of difference = 0.556
90% confidence interval of this difference:
t = 23.5520
df = 20
Answer:
First part = 2.
Time to land = 6 seconds.
Step-by-step explanation:
The object is at h = 0 when it land so
-5x^2 + 20x + 60 = 0
-5(x^2 - 4x) = -60
-5[(x - 2)^2 - 4] = -60
(x - 2)^2 - 4 = -60/-5 = 12
(x - 2)^2 = 16.
Solving the above:
Take the square root of both sides:
x - 2 = 4
x = 2 + 4
x = 6 seconds
Answer:
Standard deviation = 0.547
Step-by-step explanation:
Given the data
$5 for spade
$10 for any club
$20 for an ace club
Lets assume Probability of getting these cards to be
0.5, 0.20 and 0.30
Therefore, mean would be
Summation (PX) = 5×0.5 + 10×0.2 +20×0.3
Summation (PX)/n= 10.5/35 = 0.3
Standard deviation = √0.3
Standard deviation = 0.547
J + 47 = 55
j = 8
8 is the missing number.
Answer:
Integers and polynomials are both <u>closed </u>under addition, subtraction, and multiplication; however, operations on polynomials <u>can sometimes be open </u>while operations on integers <u>produce irrational results
</u>.
Step-by-step explanation:
Closed means that addition, subtraction, and multiplication of integers gives as result a new integer; and addition, subtraction, and multiplication of polynomials gives as result a new polynomial.
Operations on polynomials can sometimes be open, like in division.
Operations on integers can produce irrational results
, for example, dividing 11 by 9.
