The mean cost of domestic airfares in the United States rose to an all-time high of $375 per ticket. Airfares were based on the total ticket value, which consisted of the price charged by the airlines plus any additional taxes and fees. Assume domestic airfares are normally distributed with a standard deviation of $100. Use Table 1 in Appendix B. a. What is the probability that a domestic airfare is $550 or more (to 4 decimals)? b. What is the probability that a domestic airfare is $265 or less (to 4 decimals)? c. What if the probability that a domestic airfare is between $310 and $480 (to 4 decimals)? d. What is the cost for the 3% highest domestic airfares? (rounded to nearest dollar)
In: Statistics and Probability
The weights of a certain brand of candies are normally distributed with a mean weight of
0.85960.8596
g and a standard deviation of
0.05240.0524
g. A sample of these candies came from a package containing
440440
candies, and the package label stated that the net weight is
375.5375.5
g. (If every package has
440440
candies, the mean weight of the candies must exceed
StartFraction 375.5 Over 440 EndFraction375.5440equals=0.85340.8534
g for the net contents to weigh at least
375.5375.5
g.)
In: Statistics and Probability
PLEASE GIVE A VERY DETAILED ANSWER AS I HAVE TO WRITE A 2 PAGE PAPER!!!
Summarize the main points of the central limit theorem.
Discuss the advantages and disadvantages to having a large sample size in a research setting.
Explain whether or not you believe applying the central limit theorem always justifies having a sample large enough to do so, providing examples when possible.
In: Statistics and Probability
A worldwide organization of academics claims that the mean IQ score of its members is 118 , with a standard deviation of 15 . A randomly selected group of 35 members of this organization is tested, and the results reveal that the mean IQ score in this sample is 115.2 . If the organization's claim is correct, what is the probability of having a sample mean of 115.2 or less for a random sample of this size? Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.
In: Statistics and Probability
High school students across the nation compete in a financial capability challenge each year by taking a National Financial Capability Challenge Exam. Students who score in the top 14 percent are recognized publicly for their achievement by the Department of the Treasury. Assuming a normal distribution, how many standard deviations above the mean does a student have to score to be publicly recognized? (Round your answer to 2 decimal places.)
In: Statistics and Probability
A quality-conscious disk manufacturer wishes to know the fraction of disks his company makes which are defective.
Step 2 of 2 :
Suppose a sample of 1536floppy disks is drawn. Of these disks, 1383 were not defective. Using the data, construct the 98% confidence interval for the population proportion of disks which are defective. Round your answers to three decimal places.
In: Statistics and Probability
Refer to the accompanying data set of mean drive-through service times at dinner in seconds at two fast food restaurants. Construct a 99% confidence interval estimate of the mean drive-through service time for Restaurant X at dinner; then do the same for Restaurant Y. Compare the results. LOADING... Click the icon to view the data on drive-through service times. Construct a 99% confidence interval of the mean drive-through service times at dinner for Restaurant X.
Restaurant X Restaurant Y
83 104
117 123
115 156
142 117
263 171
180 136
121 112
151 124
162 125
217 127
331 129
303 134
177 232
109 212
157 291
150 125
92 99
233 137
235 242
185 145
155 142
195 202
168 146
120 145
67 134
197 144
174 161
117 131
146 172
175 130
193 240
199 237
227 254
192 239
347 237
305 172
215 85
195 105
182 52
186 175
102 81
143 143
180 141
152 97
176 128
153 149
168 131
125 189
137 154
312 131
In: Statistics and Probability
In: Statistics and Probability
Suppose a simple random sample of size n=64 is obtained from a population with μ=76 and σ=8.
(a) Describe the sampling distribution of x̅
(b) What is P (x̅ > 77.7)?
(c) What is P (x̅ ≤ 73.65)?
(d) What is P (74.5 < x̅ < 78.15)?
In: Statistics and Probability
A group of engineers developed a new design for a steel cable. They need to estimate the amount of weight the cable can hold. The weight limit will be reported on cable packaging. The engineers take a random sample of 40 cables and apply weights to each of them until they break. The 40 cables have a mean breaking weight of 775.3 lb. The standard deviation of the breaking weight for the sample is 14.9 lb. Find the 90% confidence interval to estimate the mean breaking weight for this type cable. ( , ) Your answer should be rounded to 2 decimal places.
In: Statistics and Probability
The central limit theorem is an important concept in research. It allows several key assumptions to be made, and facilitates several key practices. ImplicationsFor this discussion, you will reflect on the application of the central limit theorem to research. Develop the main response in which you address the following
Give as much detail as possible!!! |
In: Statistics and Probability
In: Statistics and Probability
Information for Problems 1 - 5: Photoresist is a light sensitive material used in industrial processes like photolithography and photoengraving to form a patterned coating on a surface. There are two types of photoresists: positive and negative. A positive photoresist is one in which the portion of the photoresist that is exposed to light becomes soluble to the photoresist developer. A negative photoresist is one in which the portion of the photoresist that is exposed to light becomes insoluble to the photoresist developer. Suppose the thickness, x, of photoresist applied to wafers in semiconductor manufacturing at a particular location on the wafer is uniformly distributed between 0.2150 and 0.2350 micrometers.
1. Find the probability distribution function for x.
2. Find the cumulative distribution function of photoresist thickness.
3. Determine the proportion of wafers that exceed 0.2275 micrometers in photoresist thickness.
4. What is the minimum thickness that is exceeded by 30% of the wafers?
5. Determine the mean of the photoresist thickness.
Information for Problems 6 - 10: Cholesterol is a fatty substance that is an important part of the outer lining (membrane) of cells in the body of animals. Its normal range for an adult is 120-240 mg/dl. The Food and Nutrition Institute (FNI) of the Philippines found that the total cholesterol level for Filipino adults has a mean, µ, of 148.9 mg/dl. Furthermore, the FNI reports that 92% of adults have a total cholesterol level below 200 mg/dl and that total cholesterol level is normally distributed.
6. What is the standard deviation of this normal distribution? Give answer to 1 decimal places.
7. An adult is considered to be at high risk for cardiovascular disease if his/her total cholesterol level is above 240.8 mg/dl. What proportion of Filipino adults are at high risk for cardiovascular disease? Give answer to 4 decimal places.
8. An adult is considered to be at moderate risk for cardiovascular disease if his/her total cholesterol level is between 200 and 240.8 mg/dl. What proportion of Filipino adults are at moderate risk for cardiovascular disease? Give answer to 4 decimal places.
9. What is the value of total cholesterol level that exceeds 90% of the Filipino population? Give answer to 2 decimal places.
10. Above what total cholesterol value will 25% of the Filipino population fall? Give answer to 2 decimal places.
Information for Problems 11 - 15: A fiber spinning process currently produces a fiber whose strength is normally distributed with a mean of 71 N/m2. The minimum acceptable strength is 65N/m2. Give answer to 4 decimal places.
11. Ten percent of the fiber produced by the current method fails to meet the minimum specification. What is the standard deviation of the fiber strengths in the current process?
12. If the mean remains at 71N/m2 and the minimum acceptable strength remains at 65N/m2, what must the standard deviation be so that only 5% of the fiber will fail to meet the specification?
13. If the mean remains at 71N/m2 and the minimum acceptable strength remains at 65N/m2, what must the standard deviation be so that only 1% of the fiber will fail to meet the specification?
14. If the standard deviation is 3N/m2, to what value must the mean be set so that only 1% of the fiber will fail to meet the minimum specification of 65N/m2?
15. If the standard deviation is 3N/m2, to what value must the mean be set so that only 2% of the fiber will fail to meet the specification of 65N/m2?
In: Statistics and Probability
In: Statistics and Probability
In: Statistics and Probability