Administer your instrument to a sample of 10 or more people. Use Excel to calculate the mean, variance and standard deviation. What did the mean, variance, and standard deviation tell you about your sample and about your instrument? Select an appropriate method for determining the reliability of this instrument. Use Excel to calculate a reliability coefficient. Explain your rationale for selecting the type of reliability that you did. Interpret the meaning of the reliability coefficient that you obtained. Discuss ways to improve the reliability coefficient of your instrument. Select an appropriate method for determining the validity of this instrument. Use excel to calculate a validity coefficient if appropriate. Explain your rationale for selecting the type of validity that you did. Interpret the meaning of the validity that you obtained. Discuss ways to improve the validity of your instrument.