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14.You are testing chocolate chip cookies to estimate the mean number of chips per cookie. You sample 25 cookies and you find a sample mean of 10 chips per cookie. Assume the standard deviations is 2. Find a 95% confidence interval and explain what that means.

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14.You are testing chocolate chip cookies to estimate the mean number of chips per cookie. You
sample 25 cookies and you find a sample mean of 10 chips per cookie. Assume the standard
deviations is 2. Find a 95%  confidence interval and explain what that means.

14.You are testing chocolate chip cookies to estimate the mean number of chips per cookie. You sample 25 cookies and you find a sample mean of 10 chips per cookie. Assume the standard deviations is 2. Find a 95% confidence interval and explain what that means.

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KylaElite · Tutor for 8 years

Answer

The 95% confidence interval is calculated as follows:<br />\[ \bar{x} \pm z \left(\frac{\sigma}{\sqrt{n}}\right) \]<br />\[ 10 \pm 1.96 \left(\frac{2}{\sqrt{25}}\right) \]<br />\[ 10 \pm 1.96 \left(\frac{2}{5}\right) \]<br />\[ 10 \pm 1.96 \times 0.4 \]<br />\[ 10 \pm 0.784 \]<br /><br />Thus, the 95% confidence interval is:<br />\[ (10 - 0.784, 10 + 0.784) \]<br />\[ (9.216, 10.784) \]<br /><br />This means we are 95% confident that the true mean number of chocolate chips per cookie lies between 9.216 and 10.784.

Explain

To find a 95% confidence interval for the mean number of chocolate chips per cookie, we use the formula for the confidence interval of the mean: \( \bar{x} \pm z \left(\frac{\sigma}{\sqrt{n}}\right) \), where \( \bar{x} \) is the sample mean, \( z \) is the z-score corresponding to the desired confidence level, \( \sigma \) is the standard deviation, and \( n \) is the sample size. For a 95% confidence level, the z-score is approximately 1.96.
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