Answer:
Index fossil, any animal or plant preserved in the rock record of the Earth that is characteristic of a particular span of geologic time or environment. A useful index fossil must be distinctive or easily recognizable, abundant, and have a wide geographic distribution and a short range through time.
Step-by-step explanation:
Answer:
Step-by-step explanation:
If she had two dice, a seven is the most common roll you can get, although the odds are still against you.
To get a seven with just 1 die is impossible.
Answer:
A. reflection across the y-axiss
Step-by-step explanation:
Given:
The locations of the two points are (-4 , 8) and (-4 , -8).
To find:
The relation between two points.
From the given points (-4, 8) and (-4 , -8), it is clear that the y-coordinates are same but the sign of x-coordinates are opposite.
If a figure is reflected across the y-axis, then we change the sign of x-coordinate and the y-coordinates remain same, i.e.,
→
For (-4,8)
→ 
So, it is reflection across the y-axis.
Therefore, the correct option is A.
Answer:
Standard deviation of a normal data distribution is a measure of data dispersion.
Step-by-step explanation:
Standard deviation is used to measure dispersion which is present around the mean data.
The value of standard deviation will never be negative.
The greater the spread, the greater the standard deviation.
Steps-
1. At first, the mean value should be discovered.
2.Then find out the square of it's distance to mean value.
3.Then total the values
4.Then divide the number of data point.
5.the square root have to be taken.
Formula-
SD=
Advantage-
It is used to measure dispersion when mean is used as measure of central tendency.