Spy_girl
Dec 4, 2008, 02:53 PM
Can you please help me to solve these questions?
1. Engineers must consider the widths of heads when designing motorcycle helmets. It is known that the widths of adult male heads are normally distributed with mean of 6.1 inches and standard deviation of 1.2 inches.
A. Show a completely labeled normal distribution displaying these population parameters
B. Determine the percent of adult males having head widths that are greater than 8.5 inches
C. Determine the percent of adult males having head widths that are between 5.5 inches and 6.5 inches.
D. If an adult male is randomly selected from the population, what is the probability his head width is between 5.5 and 6.5 inches?
2. Women between the ages of 18 and 24 years have systolic blood pressures that are normally distributed with mean of 114.8 and standard deviation of 13.1
A. Show a completely labeled normal distribution displaying these population parameters.
B. What percent of women in this age bracket have systolic blood pressures that are less than 90?
C. If a doctor wants to identify the 5% of women in this age bracket who have the highest systolic blood pressures, what pressure defines this group of women?
3. A study from Consumer Reports showed that the lifetime of TV sets is normally distributed with mean of 8.2 years and standard deviation of 1.3 years. If is desired to offer a replacement guarantee on the 2% of sets with the shortest “lifetimes,” for how long should TV’s be guaranteed?
1. Engineers must consider the widths of heads when designing motorcycle helmets. It is known that the widths of adult male heads are normally distributed with mean of 6.1 inches and standard deviation of 1.2 inches.
A. Show a completely labeled normal distribution displaying these population parameters
B. Determine the percent of adult males having head widths that are greater than 8.5 inches
C. Determine the percent of adult males having head widths that are between 5.5 inches and 6.5 inches.
D. If an adult male is randomly selected from the population, what is the probability his head width is between 5.5 and 6.5 inches?
2. Women between the ages of 18 and 24 years have systolic blood pressures that are normally distributed with mean of 114.8 and standard deviation of 13.1
A. Show a completely labeled normal distribution displaying these population parameters.
B. What percent of women in this age bracket have systolic blood pressures that are less than 90?
C. If a doctor wants to identify the 5% of women in this age bracket who have the highest systolic blood pressures, what pressure defines this group of women?
3. A study from Consumer Reports showed that the lifetime of TV sets is normally distributed with mean of 8.2 years and standard deviation of 1.3 years. If is desired to offer a replacement guarantee on the 2% of sets with the shortest “lifetimes,” for how long should TV’s be guaranteed?