Answer:
Claim is false
Step-by-step explanation:
Claim : A credit reporting agency claims that the mean credit card debt in a town is greater than $3500.
n = 20
Since n <30
So we will use t test
Formula : 
s = standard deviation = 391
x = 3600
n = 20
Degree of freedom = n-1 = 20-1 = 19
α=0.10
So, using t table
= 1.72
t critical > t calculated
So we accept the null hypothesis
Hence we reject the claim that the mean credit card debt in a town is greater than $3500.
Simply add
to both sides of the equation:
Answer:
dI/dt= -0,000127 A/s
Step-by-step explanation:
From Ohm's Law we have V = IR . deriving on both sides of equality
dV/dt = dI/dt R + I dR/dt . clearing, dI/dt = 1/R (dV/dt - I dR/dt)
replacing by the values of the statement
dI/dt = 1/400Ω (-0,05 V/s - 0,02 A 0,04Ω/s) . making calculations
dI/dt = -0,0508V/s / 400Ω = -0,000127 V/sΩ. simplifying the units
dI/dt = -0,000127 A/s
Answer:
Length = 4cm
Width = 4cm
Height = 8cm
Step-by-step explanation:
The volume of the box = 128cm^3
LWH = Volume
LWH = 128cm^3
The side of the box = $1 per cm^2
The top and bottom of the box = $2 per cm^2
Let C be the cost function
C(LWH) = (1) 2H (L+W) + (2) 2LW
from LWH = 128cm^39
H = 128/LW
put H = 128/LW in equation for C(LWH)
C(LW) = (1) 2(128/LW) + (L+W) +(2) 2LW
= 256/LW(L+W) + 4LW
= 256(1/L + 1/W) + 4LW
Differentiate C with respect to L
dC/dL = 4W - 256/L^2 = 0
Differentiate C with respect to W
dC/dW = 4L - 256/W^2 = 0
The cost is minimum when the two partial derivatives equal 0
From 4W - 256/L^2 = 0
4W = 256/L^2
W = (256/L^2) 1/4
W = 64/L^2
From 4L - 256/W^2 = 0
4L = 256/W^2
L = (256/W^2) 1/4
L = 64/W^2
Since L = W,
L= W = cuberoot (64)
L = W = 4cm
Recall that H= 128/LW
H = 128/(4*4)
H= 128/16
H= 8cm
therefore;
L= 4cm
B= 4cm
H= 8cm
