Answer:
The radius of circle B is 6 times greater than the radius of circle A
The area of circle B is 36 times greater than the area of circle A
Step-by-step explanation:
we have
<em>Circle A</em>

The radius of circle A is
-----> the radius is half the diameter
<em>Circle B</em>

Compare the radius of both circles


The radius of circle B is six times greater than the radius of circle A
Remember that , if two figures are similar, then the ratio of its areas is equal to the scale factor squared
All circles are similar
In this problem the scale factor is 6
so

therefore
The area of circle B is 36 times greater than the area of circle A
Answer:
Yes
Step-by-step explanation:
I have had this question before.
Answer:
394.9 cm
Step-by-step explanation:
The formula for a cone's surface area is A = π r ( r + √r^2 + h^2 ).
r = radius
h = height
The Pythagorean theorem, a^2 + b^2 = c^2, will be needed to find the height.
Plug in the values.
a(unknown)^2 + 6^2 = 15^2
A + 36 = 255
255 - 36 = 189
√189 ≈ 13.7
Surface area formula, plug in the values.
A = 3.14 × 6 ( 6 + √6^2 + 13.7^2 )
*PEMDAS*
A = 3.14 × 6 ( 6 + √36 + 187.69 )
A = 3.14 × 6 ( 6 + √223.69 )
A = 3.14 × 6 ( 6 + 14.95 )
A = 3.14 × 6 ( 20.96 )
A = 3.14 × 125.76
A = 394.8864
*round to nearest tenth*
A = 394.9 cm
Hope this helps! :)
Answer:
68% of these phones last 3.87 years.
Step-by-step explanation:
Exponential distribution:
The exponential probability distribution, with mean m, is described by the following equation:

In which
is the decay parameter.
The probability that x is lower or equal to a is given by:

Which has the following solution:

The probability of finding a value higher than x is:

The average lifetime of a certain new cell phone is 3.4 years.
This means that 
So

68% of these phones last how long (in years)?
This is x for which:


Then






68% of these phones last 3.87 years.
Answer:
80.
Step-by-step explanation:
His total score for 5 tests = 5 * 77.4 = 387 .
Sp his score for fifth test
= 387 - (88 + 77 + 70 + 72)
= 387 - 307
= 80.