Before 1918, approximately 60% of the wolves in a region were male, and 40% were female. However, cattle ranchers in this area have made a determined effort to exterminate wolves. From 1918 to the present, approximately 70% of wolves in the region are male, and 30% are female. Biologists suspect that male wolves are more likely than females to return to an area where the population has been greatly reduced. (Round your answers to three decimal places.)
(a) Before 1918, in a random sample of 11 wolves spotted in the
region, what is the probability that 8 or more were male?
What is the probability that 8 or more were female?
What is the probability that fewer than 5 were female?
(b) For the period from 1918 to the present, in a random sample of
11 wolves spotted in the region, what is the probability that 8 or
more were male?
What is the probability that 8 or more were female?
What is the probability that fewer than 5 were female?
In: Statistics and Probability
Before 1918, approximately 60% of the wolves in a region were male, and 40% were female. However, cattle ranchers in this area have made a determined effort to exterminate wolves. From 1918 to the present, approximately 70% of wolves in the region are male, and 30% are female. Biologists suspect that male wolves are more likely than females to return to an area where the population has been greatly reduced.
(a) Before 1918, in a random sample of 9 wolves spotted in the
region, what is the probability that 6 or more were male?
What is the probability that 6 or more were female?
What is the probability that fewer than 3 were female?
(b) For the period from 1918 to the present, in a random sample of
9 wolves spotted in the region, what is the probability that 6 or
more were male?
What is the probability that 6 or more were female?
What is the probability that fewer than 3 were female?
In: Statistics and Probability
Before 1918, approximately 60% of the wolves in a region were male, and 40% were female. However, cattle ranchers in this area have made a determined effort to exterminate wolves. From 1918 to the present, approximately 65% of wolves in the region are male, and 35% are female. Biologists suspect that male wolves are more likely than females to return to an area where the population has been greatly reduced. (Round your answers to three decimal places.)
(a) Before 1918, in a random sample of 10 wolves spotted in the
region, what is the probability that 7 or more were male?
What is the probability that 7 or more were female?
What is the probability that fewer than 4 were female?
(b) For the period from 1918 to the present, in a random sample of
10 wolves spotted in the region, what is the probability that 7 or
more were male?
What is the probability that 7 or more were female?
What is the probability that fewer than 4 were female?
In: Statistics and Probability
A textile manufacturing process finds that on average, 3 flaws occur per every 260 yards of material produced. a. What is the probability of exactly 1 flaws in a 260-yard piece of material? (Round your intermediate calculations and final answer to 4 decimal places.) Probability b. What is the probability of no more than 2 flaws in a 260-yard piece of material? (Round your intermediate calculations and final answer to 4 decimal places.) Probability c. What is the probability of no flaws in a 130-yard piece of material? (Round your intermediate calculations and final answer to 4 decimal places.) Probability When answering could you please explain how you derive at the answer? When it is shown for example, as P(X=5)=(6^5)*exp(-6)/5! = 0.1606231 I am not sure how to compute that to get that answer of 0.1606231. Thank you.
In: Statistics and Probability
Suppose that 5 percent of the population of a certain town contracted the COVID19 virus. There is a medical diagnostic test for detecting the disease. But the test is not very accurate. Historical evidence shows that if a person has the virus, the probability that her/his test result will be positive is 0.9. However, the probability is 0.15 that the test result will be positive for a person who does not have the virus.
1. Define clearly the events before you answer the following questions.
2. For a person selected randomly from the town, the test result was positive. What is the probability that the person has the Corona virus?
3. What is the difference between the probability found in the previous question and the 5%? How do we call the two probabilities?
4. For a person selected randomly from the town, the test result was negative. What is the probability that the person has the Corona virus?
5. For a person selected randomly from the town, the test result was positive. What is the probability that the person does not have the Corona virus?
In: Statistics and Probability
Zared plays basketball on his high school team. One of the things he needs to practice is his free throws. On his first shot, there is a probability of 0.6 that he will make the basket. If he makes a basket, his confidence grows and the probability he makes the next shot increases by 0.05. If he misses the shot, the probability he makes the next one decreases by 0.05.
He takes 5 shots. What is the probability he makes at least 3 shots? (Hint: a tree diagram might be a helpful strategy)
This assignment is worth 10 marks. Use the
following information to guide your work:
3 marks for showing possible outcomes
5 marks for showing work
1 mark for a correct strategy to find final probability
1 mark for correct final probability
PLEASE ANSWER WITH A TREE DIAGRAM AND PLEASE DO NOT ANSWER WITH WORK SOMEONE PREVIOUSLY POSTED!!
In: Statistics and Probability
A statistical analysis of 1,000 long-distance telephone calls made by a company indicates that the length of these calls is normally distributed, with a mean of 240 seconds and a standard deviation of 30 seconds. Complete parts (a) through (d).
a. What is the probability that a call lasted less than 180 seconds? The probability that a call lasted less than 180 seconds is nothing. (Round to four decimal places as needed.)
b. What is the probability that a call lasted between 180 and 290 seconds? The probability that a call lasted between 180 and 290 seconds is nothing. (Round to four decimal places as needed.)
c. What is the probability that a call lasted more than 290 seconds? The probability that a call lasted more than 290 seconds nothing. (Round to four decimal places as needed.)
d. What is the length of a call if only 0.5 % of all calls are shorter? 0.5% of the calls are shorter than nothing seconds. (Round to two decimal places as needed.)
In: Statistics and Probability
A recent study conducted by a health statistics center found that 27% of households in a certain country had no landline service. This raises concerns about the accuracy of certain surveys, as they depend on random-digit dialing to households via landlines. Pick five households from this country at random.
a) What is the probability that all five of them have a landline?
b) What is the probability that at least one of them does not have a landline?
c) What is the probability that at least one of them does have a landline?
A national survey found that 45% of adults ages 25-29 had only a cell phone and no landline. Suppose that three 25-29-year-olds are randomly selected.
a) What is the probability that all of these adults have only a cell phone and no landline?
b) What is the probability that none of these adults have only a cell phone and no landline?
c) What is the probability that at least one of these adults has only a cell phone and no landline?
In: Statistics and Probability
The overhead reach distances of adult females are normally distributed with a mean of
205 cm
and a standard deviation of
8 cm
a. Find the probability that an individual distance is greater than
217.502 17.50
cm.b. Find the probability that the mean for
20
randomly selected distances is greater than 203.50 cm.
c. Why can the normal distribution be used in part (b), even though the sample size does not exceed 30?
a. The probability is 0.0591.
(Round to four decimal places as needed.)
b. The probability is ..........
An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between
130 lb and
171 lb. The new population of pilots has normally distributed weights with a mean of 135 lb
and a standard deviation of 30.1 lb
a. If a pilot is randomly selected, find the probability that his weight is between
130 lb and 171 lb. The probability is approximately....... (Round to four decimal places as needed.)
In: Statistics and Probability
Given a normal distribution with mu equals 100 and sigma equals 10 comma complete parts (a) through (d). cumulative standardized normal distribution table.
a. What is the probability that Upper X greater than 80?
The probability that Upper X greater than 80 is . (Round to four decimal places as needed.)
b. What is the probability that Upper X less than 95?
The probability that Upper X less than 95 is . (Round to four decimal places as needed.)
c. What is the probability that Upper X less than 85 or Upper X greater than 110?
The probability that Upper X less than 85 or Upper X greater than 110 is . (Round to four decimal places as needed.)
d. 80% of the values are between what two X-values (symmetrically distributed around the mean)?
80% of the values are greater than nothing and less than . (Round to two decimal places as needed.)
In: Math