Answer:
A = 7,241.2454026112 square mm.
or exact : A = 2,304.96*π sq mm
Step-by-step explanation:
Cylinder formula: A = π* r^2 + 2 *π * r* h + π*r^2
is the surface area.
d = 2r = 39.2 mm
h = 39.2 mm
r = 19.6 mm
A = π* r^2 + 2 *π * r* h + π*r^2
A = 2* π* (19.6)^2 + 2π (19.6)*(39.2)
A = 2,413.748467537 + 4,827.496935
A = 7,241.2454026112 square mm.
or
A = 2*pi* (768.32 + 384.16)
A = 2*1,152.48* pi
A = 2,304.96*π sq mm
Answer: 0.6812
Step-by-step explanation:
Let p be the population proportion of trees are infested by a bark beetle.
As per given: p= 12%= 0.12
Sample size : n= 1000
Number of trees affected in sample = 1000
Sample proportion of trees are infested by a bark beetle. = 
Now, the z-test statistic : 
So, 
Hence, the value of the z-test statistic = 0.6812 .
Since there are no numbers, i will assume that the length of recess is 1 minute, or x. if social studies is 4 more than 2 times the length of recess, we can use the equation x*2+4 to solve the problem. the end result will be 6 minutes. Social studies is 6 minutes longer than recess
Answer:
25
Step-by-step explanation:
We need to set up a system of equations, then solve for the number of board markers.
Let r represent red pens, let b represent board markers.
She has 41 items, so our first equation is r+b=41.
The total cost is $46.30, so our second equation is .55r+1.5b=46.3.
r+b=41
.55r+1.5b=46.3
Let's use substitution.
r+b=41
r=41-b
.55r+1.5b=46.3
.55(41-b)+1.5b=46.3
22.55-.55b+1.5b=46.3
22.55+.95b=46.3
.95b=23.75
b=25
He bought 25 board markers.
