The Practice of Statistics

It was found that in a sample of 90 teenage boys, 63 of them have received speeding tickets.  What is the 90% confidence interval of the true proportion of teenage boys who have received speeding tickets? 

• (0.621, 0.780)

• (0.591, 0.812)

• (0.584, 0.830)

• (0.615, 0.805)

In a survey of 104 students, it was found that 79 went to the homecoming game this year. Calculate a 99% confidence interval for p.

• (0.652, 0.868)

• (0.691, 0.829)

• (0.678, 0.842(

• (0.685, 0.895)

A survey of 800 women shoppers found that 136 of them shop on impulse.  What is the 98% confidence interval for the true proportion of women shoppers who shop on impulse? 

• 0.148 < p < 0.192

• 0.136 < p < 0.204

• 0.144 < p < 0.196

• 0.139 < p < 0.201

In statistics, what does this symbol represent?

• sample mean

• population mean

• sample standard deviation

• population variance

Choose the statistical question:

• What time did you wake up this morning?

• What time do 12th graders wake up each morning during the school week?

In statistics, what does this symbol represent?

• sample mean

• population mean

• sample standard deviation

• population standard deviation

A random sample of 100 WHS students found that 53 of them were in possession of a pencil. What is the p-hat for this sample?

• 0.53

• 0.5

• 0.47

• 1

The symbol for the sample proportion is __________.

• Z_c

• p̂

• E

• q

Between what two standard deviations of a normal distribution contain 68% of the data? (empirical rule)

• one below and one above

• two below and two above

• two below and zero

• zero and two above

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have more than 7 accidents? (normalCDF)

• 0.3446

• 0.2856

• 0.4

• 0.6554