84 is no less than 7 times K, 84 divided by 7= 12,
K=12
Why not? Because every math system you've ever worked with has obeyed these properties! You have never dealt with a system where a×b did not in fact equal b×a, for instance, or where (a×b)×c did not equal a×(b×c). Which is why the properties probably seem somewhat pointless to you. Don't worry about their "relevance" for now; just make sure you can keep the properties straight so you can pass the next test. The lesson below explains how I kept track of the properties.
Answer:each box cost =$3
Step-by-step explanation:
Amount of money Ms Hart has to spent on costume boxes=$40
Amount gotten as change after purchase=$4
Amount actually used up buying costume boxes =$40-$4=36
Since she bought 12 boxes , each box cost =$36/ 12=$3
Answer:2.8333
Step-by-step explanation:
Answer:
0.2805
Step-by-step explanation:
Given that p = 20% = 0.2, n = 300.
The mean (μ) = np = 0.2 * 300 = 60
The standard deviation (σ) = 
The z score is used to determine by how many standard deviations the raw score is above or below the mean. The z score is given by:

For x = 57:

For x = 62:

From the normal distribution table, P(57 < x < 62) = P(-0.43 < z < 0.29) = P(z < 0.29) - P(z < -0.43) = 0.6141 - 0.3336 = 0.2805