he Iowa Department of Transportation repaired hundreds of bridges in 1993. To check the average cost to repair a bridge, a random sample of n = 55 bridges was chosen. The mean and standard deviation for the sample are $25,788 and $1,540, respectively. Records from previous years indicate an average bridge repair cost was $25,003. Use the sample data to test that the 1993 mean is greater than $25,003. Use α = 0.05. What is the null and alternate hypothesis?   A. H0: mu=25788 vs. Ha:mu not equal 25788   B. H0: xbar=25788 vs. Ha:xbar not equal 25788   C. H0: xbar=25003 vs. Ha:xbar not equal 25003   D. H0: mu=25003 vs. Ha:mu not equal 25003

The life span of Duracell batteries is normally distributed. The mean life span is 10,502 hours an the standard deviation is 415 hours. If 66,500 duracell batteries are manufactured, approximately how many of those batteries last at least 9,850 hours? A 39,900 B. 46,600 C. 59,900 D. 62,600

218 234 210 | 261 | 265 175 191 | 308 253 295 253 | 220 | 234 | 232 189 208 190 202 159 | 304 275 | 305 308 295

Use z scores to compare the given values. In a recent awards ceremony, the age of the winner for best actor was 28 and the age of the winner for best actress was 44. For all best actors, the mean age is 42.3 years and the standard deviation is 8.4 years. For all best actresses, the mean age is 33.3 years and the standard deviation is 10.7 years. (All ages are determined at the time of the awards ceremony.) Relative to their genders, who had the more extreme age when winning the award, the actor or the actress? Explain. Since the z score for the actor is z = and the z score for the actress is z=, the had the more extreme age. (Round to two decimal places.)

The director of research and development is testing a new medicine. She wants to know if there is evidence at the 0.02 level that the medicine relieves pain in more than 346 seconds. For a sample of 58 patients, the mean time in which the medicine relieved pain was 352 seconds. Assume the population standard deviation is 23. Find the P-value of the test statistic. 囲 Tables E Keypad Keyboard Shortcuts 0.0582 %3D IX

Use z scores to compare the given values.   In a recent awards​ ceremony, the age of the winner for best actor was 27 and the age of the winner for best actress were 47. For all best​ actors, the mean age is 42.7 years and the standard deviation is 7.7 years. For all best​ actresses, the mean age is 32.9 years and the standard deviation is 11.2 years.​ (All ages are determined at the time of the awards​ ceremony.) Relative to their​ genders, who had the more extreme age when winning the​ award, the actor or the​ actress? Explain. Since the z score for the actor is z= and the z score for the actress is z=​,the▼actress actor had the more extreme age.