Can someone please help me with this?

a) The two events are independent because they do not depend each other since the marbles are replaced. To find the total probability of two independent events, you multiply the probability of each event together.

Probability is represented by the amount of desirable outcomes over the total number of outcomes. The total would be the number of marbles, which is: 8 + 4 + 5 + 2 + 1 = 20 outcomes. The number of orange marbles is 2, so the outcomes where you do not pick orange are 20 - 2 or 18 outcomes. The probability of not picking an orange marble would be 18 / 20 or 9 / 10 (using the formula for probability).

There is one outcome where we can pick a blue marble, so the probability of picking a blue marble is 1 / 20. Now, we need to multiply the probabilities for each event: 1 / 20 * 9 / 10 = 9 / 200

b)There are 5 green marbles and 8 red marbles, so the the total outcomes where you pick green or red is 13. We put that over our total to get 13 / 20.

There are 4 purple marbles, so the probability of picking purple is 4 / 20 or 1 / 5. Now we multiply the two probabilities to get the total probability: 1 / 5 * 13 / 20 = 13 / 100

6 0

3 years ago

In a study of the impact of smoking on birth weight, researchers analyze birth weights (in grams) for babies born to 189 women w

kompoz [17]

Answer:

c. Smoking is associated with lower birth weights. When smokers are compared to nonsmokers, we are 95% confident that the mean weight of babies born to nonsmokers will be between 76.5 grams to 486.9 grams more than the mean birth weight of babies born to smokers.

Step-by-step explanation:

The difference in mean birth weights (nonsmokers minus smokers) is 281.7 grams with a margin of error of 205.2 grams with 95% confidence.

Then, we know that the 95% confidence interval is (76.5, 486.9)

$LL=M-MOE=281.7-205.2=76.5\\\\UL=M-MOE=281.7+205.2=486.9$

a. We are 95% confident that smoking causes lower birth weights by an average of between 76.5 grams to 486.9 grams.

False, it interprets the confidence interval as a probability for individual cases. The confidence interval is a range for the population mean.

b. There is a 95% chance that if a woman smokes during pregnancy her baby will weigh between 76.5 grams to 486.9 grams less than if she did not smoke.

False, it interprets the confidence interval as a probability for individual cases. The confidence interval is a range for the population mean.

c. Smoking is associated with lower birth weights. When smokers are compared to nonsmokers, we are 95% confident that the mean weight of babies born to nonsmokers will be between 76.5 grams to 486.9 grams more than the mean birth weight of babies born to smokers.

True.

d. With such a large margin of error, this study does not suggest that there is a difference in mean birth weights when we compare smokers to nonsmokers.

There is enough evidence, as the lower bound of the confidence is positive. This means that there is only a probability of 0.05/2=0.025 that the true mean weight difference is smaller than 76.5 grams.

6 0

4 years ago

SteelDrivers 78 miles on 3 gallons of gas find the miles per gallon

Neko [114]

78 divided by 3 = 25

4 0

4 years ago