Answer:
Step-by-step explanation:
d
Use the estimate but that should be more than the exact price
The confidence interval would be (10.44, 12.16). This means that if we take repeated samples, the true mean lies in 90% of these intervals.
To find the confidence interval, we use:

We first find the z-value associated with this. To do this:
Convert 90% to a decimal: 90% = 90/100 = 0.9
Subtract from 1: 1-0.9 = 0.1
Divide by 2: 0.1/2 = 0.05
Subtract from 1: 1-0.05 = 0.95
Using a z-table (http://www.z-table.com) we see that this is directly between two z-scores, 1.64 and 1.65; we will use 1.645:
5,695= 67x85 that's the answer
To find the answer, you must first turn the fractions into decimals. 4 ÷ 5 = 0.8 ; 1 ÷ 2 = 0.5 ; 1 ÷ 10 = 0.1. Then you must subtract 0.5 from 0.8. Then add 0.1 to 0.3 .