Teacher's Salary The average teacher's salary in a particular state is $\$ 54,166$. If the standard deviation is $\$ 10,200$, find the salaries corresponding to the following $z$ scores. \

$$2.5$$

Teacher's Salary The average teacher's salary in a particular state is $\$ 54,166$. If the standard deviation is $\$ 10,200$, find the salaries corresponding to the following $z$ scores. \

$$-1$$

Teacher's Salary The average teacher's salary in a particular state is $\$ 54,166$. If the standard deviation is $\$ 10,200$, find the salaries corresponding to the following $z$ scores. \

$$-1.6$$

Assume that the sample is taken fro ma large population and the correction factor can be ignored.
Teachers' Salaries in North Dakota The average teacher's salary in North Dakota is $\$37,764.$ Assume a normal distribution with $\sigma=\$ 5100$.
What is the probability that a randomly selected teacher's salary is greater than $\$ 45,000$ ?

The mean annual salary for a random sample of 300 kindergarten through 12 th grade teachers in a particular state is 50,500. The standard deviation among the state's entire population of teachers is 3,700. Find a 95 dollar confidence interval for the mean annual salary $\mu$for all kindergarten through 12 th grade teachers in the state.

Eighty randomly selected batteries were tested to determine their lifetimes (in hours). The following frequency distribution was obtained. Find the variance and standard deviation for the data.

Can it be concluded that the lifetimes of these brands of batteries are consistent?

Marriage Age for Females The mean age at which females marry is $24.6$. The standard deviation is $3.2$ years. Find the corresponding $z$ score for each. \

$$22$$

Marriage Age for Females The mean age at which females marry is $24.6$. The standard deviation is $3.2$ years. Find the corresponding $z$ score for each. \

$$18$$

Vacation Days If the average number of vacation days for a selection of various countries has a mean of $29.4$ days and a standard deviation of $8.6$ days, find the $z$ scores for the average number of vacation days in each of these countries. \

$$\begin{array}{ll}\text { Canada } & 26 \text { days } \\ \text { Italy } & 42 \text { days } \\ \text { United States } & 13 \text { days } \\ \end{array}$$

Marriage Age for Females The mean age at which females marry is $24.6$. The standard deviation is $3.2$ years. Find the corresponding $z$ score for each. \

$$26$$

Marriage Age for Females The mean age at which females marry is $24.6$. The standard deviation is $3.2$ years. Find the corresponding $z$ score for each. \

$$27$$

In a statistics class there are 18 juniors and 10 seniors; 6 of the seniors are females, and 12 of the juniors are males. If a student is selected at random, find the probability of selecting (a) A junior or a female. (b) A senior or a female. (c) A junior or a senior.

Marriage Age for Females The mean age at which females marry is $24.6$. The standard deviation is $3.2$ years. Find the corresponding $z$ score for each. \

$$31$$

Final Grade An instructor grades exams, 20%; term paper, $30 \%$; final exam, $50 \%$. A student had grades of 83,72, and 90, respectively, for exams, term papers, and final exams. Determine the student's final average. Use the weighted mean.