If the estimated population standard deviation based on previous studies is 20 percent, the acceptable error is plus or minus 5 percent, and the z-value for a 95 percent level of confidence is 1.96, the needed sample size is approximately:

The needed sample size is approximately 61.46 individuals.

Step-by-step explanation:

We can use the following formula to obtain the sample size:

Where is the standard deviation, is the quantile of the normal distribution with area of and is the acceptable error.

We would need a sample size of 62 individuals.

on monday rodney ate 1/4th of the sandwich = 3/12

on tuesday he ate 1/3rd of the sandwich = 4/12

therefore in total he has eaten = 3/12 + 4/12 = 7/12

thus we can say that he has eaten 7/12 of the sandwich on monday and tuesday alltogether.

happy to

pls mark as brainliest.

1. perpendicular

2. parallel

3. perpendicular