1. A developmental psychologist would also like to determine how much fine motor skill improves for children from age 3 to age 4 but is worried about practice effects. She takes a random sample of 9 three-year old children and a second sample of 9 four-year olds and measures fine motor skill in each using the same test described above. Her data are provided below. Three Year Olds: 40, 35, 38, 39, 40, 50, 40, 38, 42 Four Year Olds: 35, 36, 39, 29, 35, 34, 33, 34, 35 a. Is there a significant difference in the motor skills from age three to four? Test with an α = 0.01. b. What type of error is possible based on the outcome? c. Calculate and interpret the effect size. d. What is the mean motor skill score for the age three children? What is the mean motor skill score for the age four children?
1. A developmental psychologist would also like to determine how much fine motor skill improves for children from age 3 to age 4 but is worried about practice effects. She takes a random sample of 9 three-year old children and a second sample of 9 four-year olds and measures fine motor skill in each using the same test described above. Her data are provided below.
Three Year Olds: 40, 35, 38, 39, 40, 50, 40, 38, 42
Four Year Olds: 35, 36, 39, 29, 35, 34, 33, 34, 35
a. Is there a significant difference in the motor skills from age three to four? Test with an α = 0.01.
b. What type of error is possible based on the outcome?
c. Calculate and interpret the effect size.
d. What is the mean motor skill score for the age three children? What is the mean motor skill score for the age four children?
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 3 images
