Most psychological disorders strike by early adulthood. The symptoms of __________ appear around age 10;________ tends to appear later, around age 25. a. schizophrenia; bipolar disorder b. bipolar disorder; schizophrenia c. major depression; phobias d. phobias; major depression

What are the symptoms of major depression? How is major depression different from other mood disorders?

What were the three major causes of the Depression?

Which disorder is characterized by severe mood swings, intense energy, and intense sadness? a. dysthymia c. cyclothymia b. bipolar disorder d. major depression

Common symptoms of major depressive disorder include all of the following except $\underline{\phantom{\text{xxx}}}$.

a. periods of extreme elation and euphoria

b. difficulty concentrating and making decisions

c. loss of interest or pleasure in usual activities

d. psychomotor agitation and retardation

A researcher studying public opinion of propose d Social Security changes obtains a simple random sample of 50 adult Americans and asks them whether or not they support the propose d changes. To say that the distribution of $\hat{p}$, the sample proportion of adults who respond yes, is approximately normal, how many more adult Americans does the researcher need to sample if

10% of all adult Americans support the changes?

The reading speed of second grade students is approximately normal, with a mean of 90 words per minute (wpm) and a standard deviation of 10 wpm.

What is the probability a randomly selected student will read more than 95 words per minute?

Exit polling is a popular technique used to determine the outcome of an election prior to results being tallied. Suppose a referendum to increase funding for education is on the ballot in a large town (voting population over 100,000). An exit poll of 310 voters finds that 164 voted for the referendum. How likely are the results of your sample if the population proportion of voters in the town in favor of the referendum is 0.49? Based on your result, comment on the dangers of using exit polling to call elections. Include a discussion of the potential nonsampling error that could disrupt your findings.

The shape of the distribution of the time required to get an oil change at a 10-minute oil-change facility is unknown. However, records indicate that the mean time for an oil change is 11.4 minutes, and the standard deviation for oil-change time is 3.2 minutes.

To compute probabilities regarding the sample mean using the normal model, what size sample would be required?

A new reading program may reduce the number of elementary school students who read below grade level. The company that developed this program supplied materials and teacher training for a large-scale test involving nearly 8500 children in several different school districts. Statistical analysis of the results showed that the percentage of students who did not meet the grade-level goal was reduced from 15.9% to 15.1 %. The hypothesis that the new reading program produced no improvement was rejected with a P-value of 0.023.

Even though this reading method has been shown to be significantly better, why might you not recommend that your local school adopt it?

The reading speed of sixth-grade students is approximately normal, with a mean speed of 125 words per minute and a standard deviation of 24 words per minute.

What is the reading speed of a sixth-grader whose reading speed is at the 90th percentile?

A new reading program may reduce the number of elementary school students who read below grade level. The company that developed this program supplied materials and teacher training for a large-scale test involving nearly 8500 children in several different school districts. Statistical analysis of the results showed that the percentage of students who did not meet the grade-level goal was reduced from 15.9% to 15.1 %. The hypothesis that the new reading program produced no improvement was rejected with a P-value of 0.023. Explain what the P-value means in this context.

Suppose Jack and Diane are each attempting to use simulation to describe the sampling distribution from a population that is skewed left with mean 50 and standard deviation 10. Jack obtains 1000 random samples of size n=3 from the population, finds the mean of the 1000 samples, draws a histogram of the means, finds the mean of the means, and determines the standard deviation of the means. Diane does the same simulation, but obtains 1000 random samples of size n=30 from the population.

Describe the shape you expect for Jack's distribution of sample means. Describe the shape you expect for Diane's distribution of sample means.

The amount of time Americans spend watching television is closely monitored by firms such as AC Nielsen because this helps determine advertising pricing for commercials.

Do you think the variable "weekly time spent watching television" would be normally distributed? If not, what shape would you expect the variable to have?