Answer:
A sample of 997 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the z-score that has a p-value of
.
The margin of error is of:

A previous study indicates that the proportion of left-handed golfers is 8%.
This means that 
98% confidence level
So
, z is the value of Z that has a p-value of
, so
.
How large a sample is needed in order to be 98% confident that the sample proportion will not differ from the true proportion by more than 2%?
This is n for which M = 0.02. So






Rounding up:
A sample of 997 is needed.
Answer:
1.) There are 16 juniors and 8 seniors in the Chess Club. If the club members decide to send 9 juniors to a tournament, how many different possibilities are there?
(16 over 9) = 16!/(9!*7!) = 11440
2.) How many different ways can 3 cards be drawn from a deck of 52 cards without replacement?
52*51*50 = 132600
3.) How many different ways can 3 cards be drawn from a deck of 52 cards with replacement?
52^3 = 140608
4.) A corporation has 5 officers to choose from which 3 are selected to comprise the board of directors. How many combinations are there?
(5 over 3) = 5!/(3! * 2!) = 10
5.) A combination lock has the numbers 1 to 40 on each of three consecutive tumblers. What is the probability of opening the lock in ten tries?
10/40^3 = 1/6400
Answer:
wait im a little confused sorry but im going to try my best
Step-by-step explanation:
50x2=100. 5×2=10. 500x2=1,000
1,000÷10=100. 100÷10=10. 10,000÷10=1,000
Since Joann receives $10 per hour for the first 35 hours, so she receives $350 (35 times $10) before she starts receiving extra hours.
Since she received $515, we know that she worked extra hours.
Let's use the variable x to represent the number of extra hours worked.
So we can write the following equation for the total payment received:

She worked 11 extra hours. Adding this to the 35 regular hours, so she worked for 46 hours.