Answer:
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try!
Step-by-step explanation:
Answer:
see explanation
Step-by-step explanation:
These are the terms of an arithmetic sequence with n th term
= a + (n - 1)d
where a is the first term and d the common difference
d = 25 - 20 = 30 - 25 = 5 and a = 20, hence
= 20 + 5(n - 1) = 20 + 5n - 5 = 5n + 15 ← n th term formula
Answer:
b
Step-by-step explanation:
Answer:
Option B) Reject null hypothesis
Step-by-step explanation:
We are given the following in the question:
We are given the null hypothesis:



Two tailed z-test
Now, 
Since,
The calculated z-statistic does not lie in the acceptance region, we fail to accept and reject the null hypothesis.
Left-tailed z-test
Now, 
Since,

We fail to accept and reject the null hypothesis.
Right-tailed z-test
Now, 
Since,

We fail to accept and reject the null hypothesis.