In: Statistics and Probability
1.
Sales (in thousands of dollars) over 5 days at 4 different stores are recorded below.
Store 1 | Store 2 | Store 3 | Store 4 |
10 | 20 | 13 | 30 |
15 | 20 | 17 | 25 |
10 | 25 | 15 | 30 |
20 | 15 | 20 | 35 |
20 | 20 | 14 | 30 |
Test the claim that there is a significant difference among the mean amount of sales at the 4 stores, using α=0.05. Round you answer to 3 decimal places.
Group of answer choices
p-value=0.000, evidence support claim
p-value=0.578, evidence support claim
p-value=3.796, evidence not support claim
p-value=0.578, evidence not support claim
p-value=0.000, evidence not support claim
2.
We randomly sample 200 adults and ask whether they like plain, peanuts or almond M&M's. The result is summarized according to gender. Test the claim that the preference of M&M's is independent of gender. Use α=0.01. Round your answer to 3 decimal places.
Plain | Peanuts | Almond | |
Male | 40 | 50 | 20 |
Female | 50 | 20 | 20 |
Group of answer choices
p-value=0.237, evidence support claim
p-value=0.002, evidence not support claim
p-value=0.293, evidence support claim
p-value=0.237, evidence not support claim
p-value=0.002, evidence support claim
3.
Mr. Arnold teaches an algebra course and he gave 2 tests to the 29 students in the class. Below is a summary of how the 29 students performed on those 2 tests:
Test 1: Average=86.66, standard deviation=8.78
Test 2: Average=66.83, standard deviation=17.67
Test 1- Test 2: Average= 18.83, standard deviation=14.87
Assuming that the data are normal, we want to test the claim that students' average score from Test 1 is higher than Test 2. Use a 0.05 level of significance. Round your answer to 3 decimal places.
Group of answer choices
p-value=1.000, evidence not support claim
p-value=0.000, evidence not support claim
p-value=1.041, evidence support claim
p-value=0.000, evidence support claim
p-value=1.000, evidence support claim
1)
Applying one way ANOVA from excel: data-data analysis: one way ANOVA:
Source of Variation | SS | df | MS | F | P-value |
Between Groups | 712.4 | 3 | 237.4667 | 16.46216 | 0.0000 |
Within Groups | 230.8 | 16 | 14.425 | ||
Total | 943.2 | 19 |
p-value=0.000, evidence support claim
2)
Applying chi square test of independence: |
Expected | Ei=row total*column total/grand total | c | d | e | Total |
a | 49.50 | 38.50 | 22.00 | 110 | |
b | 40.50 | 31.50 | 18.00 | 90 | |
total | 90 | 70 | 40 | 200 | |
chi square χ2 | =(Oi-Ei)2/Ei | c | d | e | Total |
a | 1.823 | 3.435 | 0.182 | 5.4401 | |
b | 2.228 | 4.198 | 0.222 | 6.6490 | |
total | 4.0516 | 7.6335 | 0.4040 | 12.0891 | |
test statistic X2 = | 12.089 | ||||
p value = | 0.0024 |
p-value=0.002, evidence not support claim
3)
population mean μ= | 0 |
sample mean 'x̄= | 18.830 |
sample size n= | 29.00 |
std deviation s= | 14.870 |
std error ='sx=s/√n= | 2.7613 |
test stat t ='(x-μ)*√n/sx= | 6.819 |
p value = | 0.0000 |
p-value=0.000, evidence support claim