We want to estimate acidity of rainfall. Assume that σ is in the neighborhood of 0.5 pH and that you want your estimate to lie within 0.1 of µ with probability near 0.95. How many rainfalls must be included in your sample (one pH reading per rainfall)?

The number of rainfalls required to be included in the sample is 97.

Step-by-step explanation:

The information provided is:

Error = E = 0.1

Standard deviation = σ = 0.5

1 - α = 0.95

α = 0.05

The error formula is:

Compute the critical value as follows:

*Use the z-table for the critical value.

Compute the value of n as follows:

Thus, the number of rainfalls required to be included in the sample is 97.

7 weeks

step-by-step explanation:

convert each fraction to the least common multiple of 20, so 3/4 = 15/20 & 1/10 = 2/20, then divide 15 by 2 and you get a little over 7, so the food will last 7 weeks.