Question

The number of contaminating particles on a silicon wafer prior to a certain rinsing process was determined for each wafer in a sample of size 100, resulting in the following frequencies: Number of particles 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Frequency 1 2 3 12 11 15 18 10 12 4 5 3 1 2 1 a. What proportion of the sampled wafers had at least one particle

Answer 1

) What proportion of the sampled wafers had at least one particle? At least five particles? (Round your answers to two decimal places.)

Answer:

0.99

0.71

Explanation:

The total number of frequency is 100 when added together

A.

The proportion with at least one particle.

Here we are to get :

Total frequency - (frequency of cases whose particles are 0.)

= 100-1

= 99

99/100

= 0.99

B.

At least 5 particles:

Total number of frequency - (cases that have frequencies with 4 or less particles)

= 100 - (12+11+3+2+1)

= 100 - 29

= 71

71/100

= 0.71