pls answer no 3 on paper
Extracted text: The table below shows the heights of all fourth-grade students in a particular school, and the frequency of each height. Height (cm) frequency 130 131 132 133 134 135 136 137 138 7. 9. 20 38 18 12 10 5 1. Is the given set of data approximately normally distributed? Why or why not? 2. What percentage of the students is shorter than 135 cm? (Show your solution) 3. How many fourth-grade students are represented in the data? (Show your solution) 4. What is the mean height of the given set of data? (Show your solution) 5. A radar unit is used to measure speeds of cars on a motorway. The speeds are rounded off to the nearest whole number and are normally distributed with a mean of 90 km/hr and a standard deviation of 10 km/hr. What is the probability that the speed is between 70 km/hr and 80 km/hr inclusive? Show your solution and shade the region under the curve that represents the probability. 6. The length of life of an instrument produced by a machine is rounded off to the nearest tenths and is normally distributed with a mean of 12.2 months and standard deviation of 2.3 months. What is the probability that an instrument produced by this machine will last less than 8.1 months? Show your solution and shade the region under the curve that represents the probability. For items 7-8: The Principal decided that the top 30% of the class with the highest grades in statistics will be awarded. The scores are rounded off to the nearest hundredths and are approximately normally distributed with a mean of 80.51 and a standard deviation of 10.2. 7. What is the minimum score that a student should have to be awarded? Show your solution and shade the region under the curve that represents the portion of the population involved in the situation. 8. If 1500 students took the test, how many will NOT be awarded?
Already registered? Login
Not Account? Sign up
Enter your email address to reset your password
Back to Login? Click here