eople are randomly selected and the accuracy of their wristwatches is checked, with positive errors representing watches that are ahead of the correct time and negative rs representing watches that are behind the correct time. The 50 values have a mean of 102sec and a population standard deviation of 220sec. Use a 0.01 significance to test the claim that the population of all watches has a mean of Osec (use a two-sided alternative). test statistic is P-Value is

The heights of men aged 20 to 29 are normally distributed with a mean of 69.2 inches and a standard deviation of 2.9 inches. Find the 70th percentile for heights of men aged 20 to 29

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 99.3-cm and a standard deviation of 1.5-cm. For shipment, 25 steel rods are bundled together.Find P27, which is the average length separating the smallest 27% bundles from the largest 73% bundles. P27 =

Assume that the heights of men are normally distributed with a mean of 68.1inches and a standard deviation of 2.8 inches. If 64 men are randomly selected, find theprobability that they have a mean height greater than 69.1 inches.

The heights of 10 year old American children are normally distributed with a mean height of 4 feet and 5 inches (or 53 inches) and a standard deviation of 4.5 inches.In order to be allowed to go on a particular kids ride at the amusement park, children must be at least 44.9 inches tall and no more than 59.75 inches tall.What percent of 10 year old American children cannot go on the ride?

A successful basketball player has a height of 6 feet 11 ​inches, or 211 cm. Based on statistics from a data​ set, his height converts to the z score of 5.17. How many standard deviations is his height above the​ mean?

Suppose the mean number of candies in a standard vending machine bag is 47.6 with a standard deviation of 1.3 . assume that the number of candies is normally distributed what percentage of bags have less than 45 candies?

A sports writer wished to see if a football filled with helium travels farther, on average, than a football filled with air. To test this, the writer used 18 adult male volunteers. These volunteers were randomly divided into two groups of nine men each. Group 1 kicked a football that was filled with helium to the recommended pressure. Group 2 kicked a football that was filled with air to the recommended pressure. The mean yardage for Group 1 was ?¯1=300 yards with a standard deviation of ?1=8 yards. The mean yardage for Group 2 was ?¯2=296 yards with a standard deviation of ?2=6 yards. Assume the two groups of kicks are independent. Let ?1 and ?2 represent the mean yardage we would observe for the entire population represented by the volunteers if all members of this population kicked, respectively, a helium‑filled football and an air‑filled football. Assuming two‑sample ? procedures are safe to use and using Option 1 for the degrees of freedom, a 90% confidence interval for ?1−?2 is:…

The combined SAT scores for the students at a local high school are normally distributed with a mean of 1469 and a standard deviation of 296. The local college includes a minimum score of 1824 in its admission requirements. What percentage of students from this school earn scores that satisfy the admission requirement?

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 119.5-cm and a standard deviation of 2.2-cm. For shipment, 24 steel rods are bundled together.Find P75, which is the average length separating the smallest 75% bundles from the largest 25% bundles.P75 = -cm