Middle School

You want to estimate the mean weight loss of people one year after using a popular weight loss program advertised on TV. How many people on that program must be surveyed to be 95% confident that the sample mean weight loss is within 0.25 lb of the true population mean? Assume that the population standard deviation is known to be 10.6 lb.

A. 6907
B. 4865
C. 84
D. 6906

Answer :

Answer:

6907

Step-by-step explanation:

reqired sample size is [tex](\frac{t}{b} )^{2} s^{2}[/tex]

where,

crititical value (t) = 1.96 for 95% conf.

margin of error (b) = 0.25

standard deviation (s) = 10.6

Za/2 = Z0.025 = 1.96

n ≥ [tex](\frac{1.96}{0.25} )^{2} 10.6^{2}[/tex]

n >= 6906.27

n = 6907

In the question above, the given statement represent the answer as (6907).

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