Hello!Your answer is

If you use a calculator and divide 23 by 99, you will get 0.232323............
Answer ⇒
Answer:
x=6
Step-by-step explanation:
x+3=9
x+3-3=9-3
x=6
Answer:
C
Step-by-step explanation:
Let
be the 20 marks of the boys, and
be the 10 marks of the girls.
We know that the global mean was 70, meaning that

Multiplying both sides by 30 we deduce that the sum of the scores of the whole classroom is

By the same logic, we work with the marks of the boys alone: we know the average:

And we deduce the sum of the marks for the boys:

Which implies that the sum of the marks of the girls is 
And finally, the mean for the girls alone is

Answer:
The condition are
The Null hypothesis is 
The Alternative hypothesis is
The check revealed that
There is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is n = 20
The sample mean is 
The standard deviation is 
The Null hypothesis is 
The Alternative hypothesis is
So i will be making use of
level of significance to test this claim
The critical value of
from the normal distribution table is 
Generally the test statistics is mathematically evaluated as

substituting values


Looking at the value of t and
we see that
so we fail to reject the null hypothesis
This implies that there is sufficient evidence to support the claim that in a small city renowned for its music school, the average child takes at least 5 years of piano lessons.