Answer:
Rachel can conclude that 28% were able to successfully reproduce the rhythm plus or minus 5.6%
Step-by-step explanation:
To find the sample proportion that is able to successfully reproduce the rhythm = 121/425 = 0.2847 = p
Using this formula, we can calculate the margin of error
Margin of error = z*√{[p (1-p)] / n}
Where we assume a 95% level of confidence so that z* = 1.96. since one is not given, p = 0.28457 and n = 245.
Margin of error = 1.96 x √(0.28457 (1-0.28457)] / 245}
Margin of error = 1.96 x √[(0.28457 (0.7154)] / 245
= 1.96 x √(0.20/245)
= 1.96 x √0.000816
= 1.96 x 0.03
= 0.056.
Thus, Rachel can conclude that 28% were able to successfully reproduce the rhythm plus or minus 5.6%