Suppose that a researcher is interested in the possible relationship between the amount of screen time each day (X) and the IQ of school-age children (Y). She reasons that increased screen time might be related to lower IQ scores. Suppose that data on these variables were collected from 50 children, with the following outcomes: The sum of squares for daily hours of screen time is 65, the sum of squares for the IQ scores is 4675, and the sum of the products of the deviation scores is -220. Based on this information, calculate the appropriate test (by hand) at the 5% level of significance. Decide on a 1-tail or 2-tail test based on the goals of the research. Provide your answers in the spaces provided; do NOT show your work in the blanks. The value for the calculated test statistic

The Federal Bureau of Investigation (FBI) compiles data on crimes and crime rates and publishes the information in Crime in the United States. A violent crime is classified by the FBI as murder, forcible rape, robbery, or aggravated assault. The first two columns of Data set 1 give a relative-frequency distribution for (reported) violent crimes in the year 2010. A random sample of 500 violent-crime reports from last year yielded the frequency distribution shown in the first and third columns of Data set 1. At the 5% significance level, do the data provide sufficient evidence to conclude that last year's violent-crime distribution is different from the 2010 distribution? Use this information to answer the question. Click here to view the StatCrunch report. The value of the p-value is . Since the p-value distribution. (Round to four decimal places as needed.) α, we and determine that there sufficient evidence to conclude that last year's violent-crime distribution is different from the…

2. State whether the variables described have a positive correlation, a negative correlation, or no correlation. (a) Income and SAT scores (b) Length of a person's hair and how far they sit from the screen in a movie theater. (c) Hours of exercise per week and blood pressure.

What is the normalized z-score for a data point that has a value of 50 if the mean (Mu) is 560 and sigma is 55? This data point is taken from a total of 800 data point values .

A researcher speculates that because of differences in diet, Japanese children have a lower mean blood cholesterol level than U.S. children do. Suppose that the mean level for U.S. children is known to be 175. Let ? represent the true mean blood cholesterol level for Japanese children. What hypotheses should the researcher test? H0: ? = 175 versus Ha: ? > 165H0: ? = 175 versus Ha: ? < 185     H0: ? = 175 versus Ha: ? < 175H0: ? = 175 versus Ha: ? > 175H0: ? = 185 versus Ha: ? > 175

A researcher has found a strong relationship between level of education and income and concludes that “higher levels of education cause higher income.” What error has been made?

#25). Both photos are the same problem.

In a set of 48 months of data for medical the mean is 15 days and standard deviation of 4.2 how many months fewer than 19.2 days per month reported medical leave ( one standard deviation above the mean?

10) The top point in the scatter plot (6.5, 1459) is for Washington, DC. Find the predicted DC violent crime rate if x=6.5. Then find the residual for DC using the predicted violence crime rate and the actual violent crime rate (the actual crime rate is provided in the first sentence of this question). Prediction = Actual y-value = Residual =

If you look at the differences between the means, once with 10 participants and one mean with 20 participants. (same data set) One mean difference is very large, but non-significant and the other is very small, but came out significant. What could be the reason for this outcome? (My difference in means was with 10 participants: -1.1 and with 20 participants: -5.1)