How
Many tress there were a long time ago
Answer:
rewritten in commutative property: 25 x 16
simplified: 400
Step-by-step explanation:
Answer: 1) 2x+18=-15
2) -33+18
Step-by-step explanation: 1) multiply the outer number by the numbers inside the parentheses : 2 times x would = 2 because x is not by itself so it would be X=1x and you are multiplying 2x1 which = 2 and add the variable x so it would be 2×, and same with 18, you multiply 9x2 which =18 and thats how i got 2x+18 doesnt matter if i havent found the x yet because we already know what it equals to which is -15... 2) X=16.5 so to check we do 2×-16.5 which = -33 and add 18 it = -15
(IM NOT SURE ABOUT THE THRID ONE )
We can calculate (62 + 90) / 2 = 76. it's <span>known that 95% lies between the mean and twice the standard deviation. </span><span>if the mean is "μ" and the standard deviation is "σ": </span><span>μ-2σ and μ+2σ. i</span><span>f μ=76, then </span><span>76+2σ = 90, so 2σ = 14, so σ = 7.
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<span>the mean is 76 and the standard deviation 7. </span>