A law firm tracks the number of calls from new clients received per day.  They construct the probability distribution provided below.  number of calls (x) 1 2 3 4 5 6 7 P(x) 0.03 0.14 0.27 0.33 [P5] 0.04 0.02 1. Complete the table by finding P(5).   2. What is the expected number of calls per day at the firm? [exp] 3. What is the probability that the firm receives at least 3 calls on a given day?  [atleast]

The amounts spent for a one-day trip to Disneyland are bell-shaped with a mean of $171 per person and a standard deviation of $22 per person.  Use the Empirical Rule to answer the following questions.  1. What percentage of amounts are between $127 and $193?  [ans1] 2. 95% of amounts spent are between _______________.  [ans2]

A research firm is interested in estimating the mean time that it takes a letter mailed in California to arrive in New York.  A sample of 100 letters is mailed and it is found that the 95% confidence interval for the mean delivery time is 6.2 days to 8.3 days.  Use this information to answer the following questions.  1. What was the sample mean delivery time?  [samplemean] 2. What was the calculated error in the delivery time?  [error]    

The five number summary for the commute times, in minutes, of Santa Monica College students is provided below.  1. 5 2. 20 3.  35 4.  49 5. 121 Interpret the value of the third quartile in a contextualized sentence, using the method from class.  [per] of Santa Monica College Students spend [amnt] per day commuting.

The mean number of televisions per household in the U.S. is 2.24 televisions.  A researcher believes that the mean is lower in California.  A sample of 40 households in California results in a mean of 2.04 televisions with a standard deviation of 0.98 televisions.  At the 0.10 level of significance, test the claim by the researcher that the mean number of televisions per household in California is less than 2.24.  1.  What is the parameter being tested in this problem?  [paramterer] 2. Is the variable qualitative or quantitative?  [qual] 2. What are the correct null and alternative hypothesis for this problem?  [null]        a.  Ho:  

A researcher gathers data on the low overnight temperatures in a certain city during the month of October.  The five number summary is given below.  All temperature values are measured in degrees Fahrenheit.  Five-Number Summary: 1. 45oF 2. 55oF 3. 58oF 4. 63oF 5. 74oF Interpret the value of the third quartile in a contextualized sentence using the method from class.  [per] of overnight lows in this city in October were [amnt]. 

A college counselor is interested in comparing a student’s high school GPA and college GPA.  The GPA data for 5 random students is gathered and summarized in the following table.  Student 1 Student 2 Student 3 Student 4 Student 5 HS GPA 3.0 3.3 2.8 3.5 4.0 College GPA 2.7 3.5 2.6 3.1  3.8 Assume that the requirements of normalcy are met.  At the 0.05 level of significance, test the claim that a student’s high GPA is greater than a student’s college GPA. 1. What is the correct null and alternative hypothesis?  [null]      a.  Ho:  

Suppose that you determine that there is a significant linear relationship between the time a person spends sleeping the night before a cognitive test in hours (x) and their score on a cognitive test (y) and that the regression equation for the relationship is  y = 40.5 + 1.22x  Complete the following to interpret the y-intercept, if possible. [if][thenpredit][score]  

The speeds (in mph) of a sample of cars passing a certain checkpoint are measured by radar. The results are shown below measured in miles per hour (mph).  Answer the following questions based on this data set. Where rounding is necessary, round to one decimal place.  40        45        45        45        48        52        52        68       68     68 a) Find the mode(s).  [answer1] b) Find the mean. [answer2] c) Find the median. [answer3] d) Find the standard deviation. [answer4] e) Find the range.  [answer5]  

A factory is testing two different packaging machines.  For each machine a random sample of 10 boxes is chosen and the time, in seconds, that it takes to pack the box is measured.  The data is recorded in the table below.  Machine 1 Machine 2 41.9 42.3 42.9 42.1 41.8 40.8 41.5 42.9 42.7 43.0 42.8 42.9 41.4 43.4 41.2 42.2 42.7 42.6 41.9 42.0 Where rounding is necessary, round to two decimal places. 1. What is the point estimate of the mean packing time for Machine 1?  [mean1]  2. What is the point estimate of the mean packing time for Machine 2?  [mean2] 3. Find the 95% confidence interval for the difference in mean packing times for Machine 1 and Machine 2.  Assume that the conditions to compute the confidence interval are met.     We are 95% confident that the difference in the mean packing times for Machine 1 and Machine 2 is between [lower] seconds and [upper] seconds.  4. Based on the confidence interval, can you say that one of the machines has a lower mean packing time? [Yes] based on the confidence interval, we [can] say that [machine] has a lower mean packing time because [because].