jayce is testing the effectiveness of a cell phone case made out of a new type of recycled plastic. he…
jayce is testing the effectiveness of a cell phone case made out of a new type of recycled plastic. he randomly samples 20 cases from every batch of 1,000 manufactured and tests their effectiveness at protecting a phone dropped from a set height. here are the data from one sample. test result frequency highly effective (no damage to case or phone) 9 moderately effective (damage to case only) 10 ineffective (damage to case and phone) 1 what percentage of the cases in this sample are rated as moderately or highly effective? %
Answer
Explanation:
Step1: Find total number of samples
First, we need to find the total number of cases in the sample. We add up the frequencies of each test result. The frequencies are 9 (highly effective), 10 (moderately effective), and 1 (ineffective). So the total number of samples ( n = 9 + 10 + 1 ). ( n = 20 )
Step2: Find number of moderately or highly effective cases
Next, we find the number of cases that are moderately or highly effective. We add the frequency of highly effective and moderately effective. So that's ( 9 + 10 ). ( 9 + 10 = 19 )
Step3: Calculate the percentage
To find the percentage, we use the formula ( \text{Percentage} = \left( \frac{\text{Number of moderately or highly effective cases}}{\text{Total number of cases}} \right) \times 100 ). Plugging in the numbers, we have ( \frac{19}{20} \times 100 ). ( \frac{19}{20} \times 100 = 95 )
Answer:
95