(Solved): 1. Which of the following examples would use the z-distribution: x=100;=99;s=5;n=70x=7;=4;s=1;n ...

1. Which of the following examples would use the z-distribution: $\begin{array}{l}x=100;?=99;s=5;n=70\\ x=7;?=4;s=1;n=20\end{array}$ $\begin{array}{l}x=50;?=53;?=7;n=15\\ x=15;?=17;?=3;n=45\end{array}$ 2. Know how to calculate point est., confidence interval, max tolerable error. Know the effect when you change the confidence level and the sample size. A high school surveyed their graduates on their starting salaries. 300 were returned. The average starting salary of the surveys returned was $\$32,000$ with a standard deviation of $\$5,000$. A. What is the point estimate for the starting salary of the graduates? Hint: One number! B. What is the $95\%$ confidence interval for the average salary of all graduates? Hint: Range C. What is the value of the Maximum Tolerable Error for the above confidence interval?? Hint: This is the number that follows +/- in the confidence interval formula. You add it to and subrtact it from the mean! D. If the level of confidence changes to $99\%$, and all other variables remain unchanged, what will happen to the confidence interval??? E. If the number of graduates returning the survey changes from 300 to 700 , all other variables remaining unchanged, what will be effected??? (Probability of error? Point estimate? Confidence Interval?) Hint: Only one changes! 3. Know how to calculate sample size: A restaurant would like to estimate the average $\$$ amount of a take-out order. The standard deviation is $\$15$. If a $99\%$ confidence level and an interval (error) of $\$5$ is desired, how many customers should be in the sample? Hint: The formula is on the formla sheet in the "Useful Resources" Module. " $n="$