For large sample confidence intervals about the mean you have:
xBar ± z * sx / sqrt(n)
where xBar is the sample mean z is the zscore for having α% of the data in the tails, i.e., P( |Z| > z) = α sx is the sample standard deviation n is the sample size
We need only to concern ourselves with the error term of the CI, In order to find the sample size needed for a confidence interval of a given size.
z * sx / sqrt(n) = width.
so the z-score for the confidence interval of .98 is the value of z such that 0.01 is in each tail of the distribution. z = 2.326348
The equation we need to solve is:
z * sx / sqrt(n) = width
n = (z * sx / width) ^ 2.
n = ( 2.326348 * 6 / 3 ) ^ 2
n = 21.64758
Since n must be integer valued we need to take the ceiling of this solution.
n = 22
The regular hexagon has both reflection symmetry and rotation symmetry.
Reflection symmetry is present when a figure has one or more lines of symmetry. A regular hexagon has 6 lines of symmetry. It has a 6-fold rotation axis.
http://prntscr.com/96ow2n
Rotation symmetry is present when a figure can be rotated (less than 360°) and still look the same as before it was rotated. The center of rotation is a point a figure is rotated around such that the rotation symmetry holds. A regular hexagon can be rotated 6 times at an angle of 60°
<span>http://prntscr.com/96oxjx</span>
The mathematical equation for volume of a cylinder is pi times radius Squared Times height
The radius squared is 36
So 3.14 x 36 =113.04
Then you multiply 113.04 x 7 = 719.28.
Round that number and you get to 791.3.
So the answer is c
Answer:
x = 5
Step-by-step explanation:
2(x+6) = 22
2x+12 = 22
2x = 10
x = 5
Answer:
The mass of the object is 2.6 grams
Step-by-step explanation:
The density of an object is the ratio between its mass and its volume
The equation of the is d = 
, where
Let us use this equation to solve the question
∵ An object has a density of 1.3 g/cm³
∴ d = 1.3 g/cm³
∵ Its volume is 2 cm³
∴ V = 2 cm³
→ Substitute them in the equation of the denisty above
∵ 1.3 = 
→ Multiply both sides by 2
∴ 2 × 1.3 = 2 ×
∴ 2.6 = m
∴ The mass of the object is 2.6 grams
