Sarah is doing research on the average age of first-year resident physicians. She wants her estimate to be accurate to within 1 year. From past studies, she knows the population standard deviation is 8.265. How many first-year residents must she survey to be 95% confident?

The number of first-year residents she must survey to be 95% confident= 263

Step-by-step explanation:

When population standard deviation ()  is known and margin of error(E) is given, then the minimum sample size (n) is given by :-

, z* = Two-tailed critical value for the given confidence interval.

For 95% confidence level , z* = 1.96

As, = 8.265, E = 1

So,

Hence, the number of first-year residents she must survey to be 95% confident= 263

2 over 5

step-by-step explanation:

the 2: 3 ratio is the length of the ac segment to the cb segment total length. this implies that the ratio between segment ac length and segment ab length is 2: 5. point c is 2/5 from a to b, so the required fraction is 2/5.

the ratio of balloons to tables is 5: 2 and the constant variation is 5.

the equation is y=5x