In: Statistics and Probability
To study the effect of temperature on yield in a chemical process, five batches were produced at each of three temperature levels. The results follow.
Temperature | ||
---|---|---|
50°C | 60°C | 70°C |
35 | 31 | 22 |
25 | 31 | 29 |
35 | 33 | 29 |
39 | 23 | 29 |
26 | 27 | 36 |
Construct an analysis of variance table. (Round your values for MSE and F to two decimal places, and your p-value to four decimal places.)
Source of Variation |
Sum of Squares |
Degrees of Freedom |
Mean Square |
F | p-value |
---|---|---|---|---|---|
Treatments | ? | ? | ? | ? | ? |
Error | ? | ? | ? | ||
Total | ? | ? |
Use a 0.05 level of significance to test whether the temperature level has an effect on the mean yield of the process.
State the null and alternative hypotheses.
H0: μ50°C ≠
μ60°C ≠ μ70°C
Ha: μ50°C =
μ60°C = μ70°C
H0: μ50°C =
μ60°C = μ70°C
Ha: Not all the population means are
equal.
H0: At least two of the population means are
equal.
Ha: At least two of the population means are
different.
H0: μ50°C =
μ60°C = μ70°C
Ha: μ50°C ≠
μ60°C ≠ μ70°C
H0: Not all the population means are
equal.
Ha: μ50°C =
μ60°C = μ70°C
Find the value of the test statistic. (Round your answer to two decimal places.)
t stat =
Find the p-value. (Round your answer to four decimal places.)
p-value =
State your conclusion.
Reject H0. There is not sufficient evidence to conclude that the mean yields for the three temperatures are not equal.
Do not reject H0. There is sufficient evidence to conclude that the mean yields for the three temperatures are not equal.
Reject H0. There is sufficient evidence to conclude that the mean yields for the three temperatures are not equal.
Do not reject H0. There is not sufficient evidence to conclude that the mean yields for the three temperatures are not equal.
one way anova-
treatment | 50°C | 60°C | 70°C | |||
count, ni = | 5 | 5 | 5 | |||
mean , x̅ i = | 32.000 | 29.00 | 29.000 | |||
std. dev., si = | 6.164 | 4.000 | 4.950 | |||
sample variances, si^2 = | 38.000 | 16.000 | 24.500 | |||
total sum | 160 | 145 | 145 | 450 | (grand sum) | |
grand mean , x̅̅ = | Σni*x̅i/Σni = | 30.00 | ||||
square of deviation of sample mean from grand mean,( x̅ - x̅̅)² | 4.000 | 1.000 | 1.000 | |||
TOTAL | ||||||
SS(between)= SSB = Σn( x̅ - x̅̅)² = | 20.000 | 5.000 | 5.000 | 30 | ||
SS(within ) = SSW = Σ(n-1)s² = | 152.000 | 64.000 | 98.000 | 314.000 |
no. of treatment , k = 3
df between = k-1 = 2
N = Σn = 15
df within = N-k = 12
mean square between groups , MSB = SSB/k-1 =
15.0000
mean square within groups , MSW = SSW/N-k =
26.1667
F-stat = MSB/MSW = 0.5732
anova table | ||||||
SS | df | MS | F | p-value | F-critical | |
treatments | 30.00 | 2 | 15.00 | 0.57 | 0.5784 | 3.885 |
error | 314.00 | 12 | 26.17 | |||
Total: | 344.00 | 14 | ||||
α = | 0.05 |
H0: μ50°C =
μ60°C = μ70°C
Ha: Not all the population means are equal.
test stat = 0.57
p value=0.5784
Do not reject H0. There is not sufficient evidence to conclude that the mean yields for the three temperatures are not equal.