Answer:
The least number of stamps required is 
Step-by-step explanation:
Let the number of
cent stamps be
and
cent stamps be 
We have

The minimum number is obtained when more
cent stamps are used
Here
cannot be greater than
since 
Substitute 

Not possible since
is not a fraction
Substitute 

Not possible since
is not a fraction
Substitute 

Possible
Hence minimum number of stamps is

This breaks into two inequalities:
2x - 3 > 6
and
-2x + 3 > 6
------------------------
2x - 3 > 6
Add 3 to both sides:
2x > 9
Divide 2 to both sides:
x > 4.5
-----------------------
-2x + 3 > 6
Subtract 3 to both sides:
-2x > 3
Divide -2 to both sides:
x < -1.5
Take the fraction. Divide the top number by the bottom number. (That's what a fraction means.). Some fractions will produce a decimal that goes on and on and never ends. Some fractions produce a decimal that ends. Some examples that make repeating decimals are: 1/3, 1/7, 1/9, 1/11.
Answer:
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.
Step-by-step explanation:
We have the followign system of hypothesis:
Null hypothesis: 
Alternative hypothesis: 
The degrees of freedom are given by:

The significance level is
and then the critical value can be founded in th chi square table we need a quantile that accumulates 0.05 of the area in the right tail of the distribution and for this case is:

And if the chi square statistic is higher than the critical value we can reject the null hypothesis in favor of the alternative.