A random sample of 20 recent weddings in a country yolded a mean wedding cost of $26,342 38. Assume that recent wedding costs in this country are normally distributed with a standa deviation of $7900. Complete parts (a) through (c) below.
a. Determine a 95% confidence interval for the mean cost of all recent weddings in this country.

a) The 96% confidence interval is from $___ to $___
round to nearest cent

b) what’s the margin or error

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's. 

The answer is to reassure the reader about dangers of mad cow disease.

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.