I don't understand how to solve this problem and I want to fully understand it for my upcoming test

I don't understand how to solve this problem and I want to fully understand it for my upcoming test

The average for a high school math contest was 91.2. 21 girls participated in the contest with an average of 92. The boys average was 90.5. Find the number of boys who participated.

word problem I need to solve for homework. I need to know how to get the answer

The standard error of the sample mean is calculated to $1,475.73. The president wants to be able to estimate mean cost to within $1,500 of the true population mean with a probability of 80%. How many...

If female blood pressure is normally distributed with a mean of 114 and standard deviation of 19.8, find p12 and p77

In a neighborhood near Simmons, there are 280 families. The average number of members per family is 3.5. How many people live in the neighborhood? a. 980 people b. 80 people c. 900 people d...

The scores of 2500 students on an exam have an approximately normal distribution with mean of 52 points and standard deviation of 11 points. Estimate how many students more than 52 points. If necessary,...

Mean is the awseom ethin

The mean age of six persons is 49 years. The ages of five of these six persons are 56 , 34 , 40 , 51 , and 36 years. Find...

Use the frequency distribution table below showing a sample data set for 10 students on a test with a maximum score of 12 to find the mean score. Score Frequency 1...

What is a real life situation in which using the median is preferable to the mean? Number examples please!

4x+3,7,3x-2,9x

Mean : 21 Median : 13 Mode : 8 Range : 30 Mean Absolute Deviation : 11.9 Please don't make the answer too confusing. Thank you!

find the value of a

i need so much help just help m please!!!

The question: The ages, x years, of 150 cars are summarised by ∑x = 645 and ∑x2 = 8287.5 Find ∑(x-y)2 where y denotes the mean of x. The...

set of data with 1200 numbers is normally distributedwith a mean of 27 and a standard deviation of 4. how many numbers in the data would you expect to be between 23 and 31?

The average of n numbers x^1, x^2, x^3, ........, x^n is M. If x^n is replaced by x', then new average is______

The repair cost of a Subaru engine is normally distributed with a mean of $5,850 and standard deviation of $1,125. Random samples of 20 Subaru engines are drawn from this population and the mean repair...

1. Use the data set {5, 21, 21, 25, 30, 40} to find the requested values: a. Mean b. Median c. Mode d. Range e. Standard deviation