Answer: 1.303639
Step-by-step explanation:
The t-score for a level of confidence
is given by :_
, where df is the degree of freedom and
is the significance level.
Given : Level of significance : 
Then , significance level : 
Sample size : 
Then , the degree of freedom for t-distribution: 
Using the normal t-distribution table, we have

Thus, the t-score should be used to find the 80% confidence interval for the population mean =1.303639
Answer:
Point C
Step-by-step explanation:
because the number is 0.3 you need to start at zero on the number line and go forward 3 marks. That will lead you to your answer of 0.3
1.27 repeated is the answer
-7 + 4(n-1). Use this and plug in 10 for n, making it
-7 + 4(9)
-7+36
29