A dentist wanted to determine if a relationship existed between childhood fluoride exposure and cavities. She took a sample of adults in her practice and counted how many cavities each person had in his or her permanent teeth. She also determined how many years of childhood each person was exposed to tap water with fluoride. The minimum value on this variable was 0 and the maximum was 18. Using the data below, an alpha of .05 and a two-tailed test, was there a significant relationship?

Hydrogen content is conjectured to be an important factor in porosity of aluminum alloy castings. An article gives the accompanying data on x = content and y = gas porosity for one particular measurement technique. 0.18 0.20 0.21 0.21 0.21 0.22 0.23 0.23 0.24 0.24 0.25 0.28 0.30 0.37 0.48 0.71 0.42 0.44 0.55 0.44 0.24 0.48 0.22 0.82 0.86 0.72 0.70 0.74 Minitab gives the following output in a response to a Correlation command: Correlation of Hydrcon and Porosity = 0.425 (a) Test at level 0.05 to see whether the population correlation coefficient differs from o. State the appropriate null and alternative hypotheses. O Ho: p = 0 Hip 0 O Ho: p = 0 Hip + 0 O Ho: p+0 Hip = 0 Calculate the test statistic and determine the P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.) t = P-value = State the conclusion in the problem context. O Fail to reject H: The data does not suggest that the population correlation coefficient differs significantly…

Calculate the appropriate test statistic given that SSy = 20.6 and r = .5. Note: no need to put the sign in front of the value. Note: round to the nearest hundredth

A new drug has been developed to cure Ebola. Before it can be used, we need to make sure that the chance for severe side effects (including death) is under 20%. What would be an appropriate alpha value for the researchers to use, and why would that value be appropriate in this situation?

To assess the air quality in a surgical suite, the presence of colony-forming spores per cubic meter of air is measured on three successive days. The results are as follows: {12, 24, 30}. Calculate the mean and standard deviation for these data.

The average life expectancy of tires 40,000 miles. The company has rece The manager hopes to find out wheth life test, 40 tires were used, and their following SPSS results: One-Sample Statistics Std. Dev Mean time 40881.8262 40 2945 One- df Sig. (2-taile 1.893 Set up Ho: M = 40,000 %3D HA: The test statistic is 1.893 The distribution of the test stati Make the statistical decision (o Express the statistical decision

Research was conducted on the amount of oxygen runners could utilize during training, known as their VO2 max, and their finishing times for a 5K race to see if there was a significant relationship between these variables. The results for 8 runners were compiled and placed in the following table. VO2 Max (ml/kg/min) (x) 5K Finishing Time (min) (y) 16.28 34.66 20.55 37.41 18.62 34.11 15.78 37.36 18.12 37.56 39.49 23.7 26.88 28.72 43.39 20.69 Calculate the correlation coefficient. Round to three decimals. Find the equation of the regression line. Round each value to two decimals Preview Predict the time in the 5K for a runner whose VO, max is 30.12 ml/kg/min. Round your answer to two decimals Get Help: VIDEO

Analysis of several plant-food preparations for potassium ion yielded the following data:   Sample Percent K+ 1 6.02, 6.04, 5.88, 6.06, 5.82 2 7.48, 7.47, 7.29 3 3.90, 3.96, 4.16, 3.96 4 4.48, 4.65, 4.68, 4.42 5 5.29, 5.13, 5.14, 5.28, 5.20   The preparations were randomly drawn from the same population. a. Find the mean and standard deviation s for each sample b. Obtain the pooled value spooled c.Why is spooled a better estimate of s than the standard deviation from any one sample?

1. Analyze the data as a two way factorial design. Johnson and Leone (Statistics and Experimental Design in Engineering and the Physical Sciences, Wiley, 977) describe an experiment to investigate warping of copper plates. The two factors studied were the temperature and the copper content of the plates. The response variable was a measure of the amount of warping. The data were as follows: Temperature (°C) 50 75 100 125 40 17, 20 12,9 16, 12 21, 17 Copper Content (%) 60 80 16, 21 18, 13 18, 21 23, 2! 24, 22 17, 12 25, 23 23, 22 100 28, 27 27, 31 30, 23 29, 31

2. Two manufacturing companies of soap each claims that their product is superior in whitening one's complexion. A researcher did an experiment by randomly choosing two groups and assigning each group to use the product for one month. Results are shown below where the higher the number, the more effective the product in skin whitening. At 0.01 (t-tabular value is +2.88) level, is there a significant difference between the two products effectiveness in skin whitening? Product (Soap A or B) A 10 12 13 13 15 15 15 17 18 24 25 25 25 27 28 30 30 | 8 9 11 15 16 16 16 19 20 21 25 25 26 28 29 30 30 32 33 33 LO04