Question

Based on internal tests a spaghetti sauce company believes that 70% of people prefer their sauce to the competitor's sauce. They are going to conduct a taste test and want to have a probability of. 9 or better that 60% or more of taste testers prefer their product. They are considering groups of taste testers in increments of 10, i. E. , 10, 20, 30, 40,. How many people do they need to participate in the taste test? Note: Your answer will be divisible by 10 with no remainder. Use Excel to help you find the answer

Answer 1

In Excel, enter =1-BINOM.DIST(.6*TRIALS-1,TRIALS,0.7,TRUE) and try different values of TRIALS to find a value of 90% or larger.