A vendor buys milk at a certain price, adds water and sells the adulterated milk at the same rate as he bought it for. He makes
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Answer:
The correct option is 4) 0.72.
Step-by-step explanation:
Consider the provided information.
Let us consider that there are 100 members.
(Note: you can take any number the answer will remain the same.)
90% of its members drank protein shakes and of the members who drank protein shakes.
90% of 100 is 90.
Thus, 90 members drank protein shake.
Of the members who drank protein shakes, 30% took weight-loss medication.
30% of 90 is 27.
That means 27 out of 90 took weight loss medication.
Out of 100 members 90 drank protein shakes that means 10 members does not take protein shakes.
Only 10% of members who did not drink protein shakes took weight-loss medication.
10% of 10 is 1, that means 1 member out of 10 took weight loss medication.
Thus the required table is:
Medication Not Medication Total
Drank shakes 27 63 90
Doesn't Drank shakes 1 9 10
Total 28 72 100
Now we need to find the probability that a gym member does not take weight-loss medication.
72 out of 100 members does not take weight-loss medication.
Therefore, the required probability is:
Hence, the correct option is 4) 0.72.
Answer:
a) Failed to reject the null hypothesis (P-value=0.09).
b) The 95% CI for the difference in proportions is:
Step-by-step explanation:
a) We have to perform a hypothesis test for the difference of proportions.
The null and alternative hypothesis are:
The significance level is 0.05.
The proportion of the passenger cars owners is:
The proportion of commercial truck owners is:
The weigthed average p is
The estimated standard deviation is
We can calculate the z-value as:
The P-value for z=-1.362 is P=0.0866.
The P-value (0.09) is greater than the significance level (0.05), so it failed to reject the null hypothesis. There is no enough evidence to prove that commercial trucks owners violate laws requiring front license plates at a higher rate than owners of passenger cars.
b) We can construct a 95% CI, according to the significance level of 0.05.
The z-value for this CI is 1.96.
We have to recalculate the standard deviation:
The lower limit is then:
The upper limit is:
The 95% CI for the difference in proportions is:
In this case, we can conclude that the difference between the proportions, with 95% confidence, can still be equal or greater than zero, meaning that it is possible passenger car owners violate laws more than truck owners.