udaseu 8h your results to part (c). 23. Calcium in Rainwater Calcium is essentia

Question

udaseu 8h your results to part (c). 23. Calcium in Rainwater Calcium is essential to tree growth s the hine. ATM because it promotes the formation of wood and maintains cell walls. In 1990, the concentration of calcium in precipita- tion in Chautauqua, New York, was 0.11 milligrams per liter (mg/L results in the following data: ). A random sample of 10 precipitation dates in 2007 67 hat 0.065 0.183 Source: National Atmospheric Deposition Program 0.087 0.120 0.070 0.234 0.262 0.313 0.126 0.108 an hes rol ose (a) Because the sample size is small, we must verify that cal- cium concentrations are normally distributed and the sample does not have any outliers.The normal probabil- ity plot and boxplot are shown. Are the conditions for conducting the hypothesis test satisfied? Yees to Ca Concentration (mg/L) (b) Does the sample evidence suggest that calcium concen- trations have changed since 1990? Assume that = 0.08 and use the = 0.05 level of significance Ti 00 the an nH level of the rain in the

Explanation / Answer

Question 23 (a) Here in the normal probability plot, the values are in the inner range of probability plot. Similarly, the boxplot also shows that the data shows normal distribution.

(b) Here,

H0 : = 1990 = 0.11

Ha : 1990

population standard deviation = 0.08

standard error of sample mean = /n = 0.08/10 = 0.0253

Sample mean x = 0.157

Test statistic

t = (x - H)/ se0 = (0.157 - 0.11)/ 0.0253 = 1.8577

Here dF = 10 -1 = 9 ; alpha = 0.05, two tailed

tcritical = t0.05,9 = 2.2622

here, t < tcritical so we faill to reject the null hypothesis and we can conclude that sample evidence suggest that Calcium concentrations haven't changed since 1990.

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.