Sara is researching phones and decides to create a weighted average to determine the ‘best’. She uses the following weights: 50% battery life, 30% cost, 20% camera to calculate a ‘score’ for each phone. She finds the following ratings out of 10 for each category on the internet.
Battery. Cost Camera
iPhone 9 7 8
Samsung 9 7 7
Motorola 8 9 8
Calculate the weighted average ‘score’ for each phone.
(round to the tenths place)