Suppose the time it takes to wait for a red light to change to a green light is uniformly distributed between 0 and 20 seconds.   What is the probability that the wait time is greater than 15 seconds?

The length of a pregnancy from conception to natural birth among a certain female population is approximately normally distributed with a mean of 270 days and a standard deviation of 10 days. What is the percent of pregnancies that last more than 300 days? What is the percent of pregnancies that last less than 275 days? What is the percent of pregnancies that last between 265 and 285 days? How short must a pregnancy be in order to fall in the shortest 10% of all pregnancies?

A pre-school teacher has a set of data describing her students’ number of minutes of nap time and the number of tantrums in the afternoon. She has a feeling that the amount of sleep a toddler gets can contribute to whether or not they have a tantrum-free afternoon…in fact, she found that the correlation between these variables is -0.68.  The mean amount of sleep her pre-schoolers got has a mean of 92.1 minutes with a standard deviation of 8.5 and the mean number of tantrums in the afternoon is 2.4 with a standard deviation of 0.54.  With this information, what is the equation of the LSRL for number of tantrums (y) on minutes of naptime (x)?

The following chart gives the world record times for the short course women’s Butterfly (swimming)  at the end of each year given.   World Record Times – Women’s Short Course Butterfly Year Time (seconds) 1995 58.68 1996 58.29 1997 57.79 1998 56.90 2000 56.56 2002 56.34 2006 55.95 2008 55.74 2009 55.05 Using x = 5 to represent the year “1995,” what is the slope of the LSRL for the data above?

According to government data, 20% of employed women have never been married.  Assume an SRS of seven employed women are selected and asked if they have ever been married. What is the random variable X of interest here?  Define X. Out of the 7 employed women selected at random, what is the probability that exactly 2 have never been married? (Show your work below)  _________ Out of the 7 employed women selected at random, what is the probability that 2 or fewer have never been married?  ___________ What are the mean and standard deviation of X?  Mean:_________ Standard Deviation _________

A client who had a plaster splint applied to the ankle at 7 a.m. and received pain medication at 9 a.m. now at 11 a.m. reports that the pain is getting worse, not better. What is the nurse’s best first action to prevent harm?

Final_free_response

If P(D) = 0.26 and P(R) = 0.38, what is P(D or R) if D and R are independent?

Dick plays field hockey. He makes a goal 55% of the time he shoots. A = the event Dick is successful on his first goal attempt. P(A) = 0.55. B = the event Dick is successful on his second goal attempt. P(B) = 0.55. Dick tends to make goals in streaks. The probability that he makes a second goal given that he made the first goal is 0.80.   If Dick attempts two goals, what is the probability that he makes both goals?

Dick plays field hockey. He makes a goal 55% of the time he shoots. A = the event Dick is successful on his first goal attempt. P(A) = 0.55. B = the event Dick is successful on his second goal attempt. P(B) = 0.55. Dick tends to make goals in streaks. The probability that he makes a second goal given that he made the first goal is 0.80. Which of the following is true about A and B?