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Answer: Sample statistics are used to make inferences about population parameters.
Step-by-step explanation:
A number which describes a population is called a parameter, such as a proportion or percentage.
A statistic is a number which may be calculated from the data observed in a random sample without demanding the use of any unknown parameters.
The mean and variance of a population are population parameters.
Thus, fourth statement is the right answer "Sample statistics are used to make inferences about population parameters."
Answer:
B
Step-by-step explanation:
26 letters 10 numbers no repeating
P(26,2)×P(10,4)
=26×25×10×9×8×7=3276000