Statistics

Statistics

1.

a. This is a one-tailed test.

b. Ho: The use of new toothpaste does not prevent more cavities as compared to other brands of toothpastes, µ = 1.73 Ha: The use of new toothpaste prevents more cavities as compared to other brands of toothpastes, µ < 1.73

c. Using formula



Z = 1.5 - 1.73 / (1.12/)

Z = -1.64

d. z (cv) = 1.65

e. If Ho gets rejected, the research would conclude that the use of new toothpaste does prevent more cavities as compared to other brands of toothpastes

f. Using formula



95% confidence interval = 1.5 ± 1.96 (1.12 / v60)

95% confidence interval = Upper Bound: 24.03, Lower Bound: -3.19

2. 

T distribution critical value at df = 23 is ±2.0687 while the t distribution critical value at df = 13 is2.1604. Therefore, in the mentioned situation, Henry is more likely to make a type II error as he is more likely to accept the null hypothesis when it is supposed to be rejected.

3.

a. This is a two-tailed test.

b. Ho: Individual who listens to classical music will not score differently from the general population on a test of spatial ability, µ = 58.

Ha: Individual who listens to classical music will score differently from the general population on a test of spatial ability µ ? 58.

c. Using formula,

t = 59 - 58 / (3.66/)

t = 1.03

d. t cv = 1.771

e. If Ho gets rejected, the research would conclude that those individual who listen to classical music will score differently from the general population on a test of spatial ability.

f. Using formula,

95% confidence interval = 59 ± 2.16 (3.66/v14)

95% confidence interval = Upper Bound: 62.40, Lower Bound: 58

4.

a. Using Formula,

X^2 = (31 - 24)2 / 24

X^2 =2.04

b. df = n - 1

df = 120 - 1

df = 119

c. X(squared) cv = 0.05

d. The ...