The graph shows the solution to which system of equations?
1 answer:
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Answer:
Yes, evidence shows that the cream will improve the skin of more than 40% of women over the age of 50 in 0.01 significance level.
Step-by-step explanation:
We need to make a hypothesis test.
Let p be the proportion of women who used cream report skin improvement.
: p=0.4
: p<0.4
To test the hypothesis, we need to calculate z-score of the sample mean and compare its probability with the significance level.
z= where
- p(s) is the sample proportion of women reported improvement (0.5)
- p is the proportion assumed under null hypothesis. (0.4)
- N is the sample size (70)
Putting the numbers:
z= ≈ 1.71
And P(z<1.71) ≈ 0.955. Since 0.955>0.01 we fail to reject the null hypothesis that the cream will improve the skin of more than 40% of women.