Answer:
13/20
Step-by-step explanation:
To add fractions without the common denominator, you have to make them equal so
1/4 x 5 = 5/20
2/5 x 4 = 8/20
5/20 + 8/20 = 13/20
Answer:
The equation is

and the graph looks like this
Answer:
The degrees of freedom for this sample are 27.
The sample size to get a margin of error equal or less than 0.3656 is n=4450.
Step-by-step explanation:
The degrees of freedom for calculating the value of t are:

With 27 degrees of freedom and 95% confidence level, from a table we can get that the t-value is t=2.052.
The sample size to get a margin of error equal or less than 0.3656 can be calculated as:

10 because it makes the most sense