Answer: d. if we do not know the population standard deviation and must use the sample standard deviation.
Step-by-step explanation:
We use t-distribution is quite similar to distribution of z-score .
The interpretation of t-scores and z-scores are same.
T- distribution is used when the data is not accurately normal and when the population standard deviation is unknown.
In the absence of population standard deviation , we use the standard deviation of the sample.
So , We use a t distribution for inference about a population mean instead of the standard Normal distribution if we do not know the population standard deviation and must use the sample standard deviation.
Hence, the correct option is : d. if we do not know the population standard deviation and must use the sample standard deviation.
Answer:
7 to the 12th power. (The last one.)
Step-by-step explanation:
When dividing expressions with the same base you need to subtract the powers. In this case subtract 2 from 14 which makes 12. So your answer will be <u><em>7^12</em></u>.
X^2 + 2x - 15
(x - 3) (x + 5)
B. (x - 3)
X=8 is the answer.
Sorry if it’s wrong
