Answer:
Step-by-step explanation:
Since the results for the standardized test are normally distributed, we would apply the formula for normal distribution which is expressed as
z = (x - µ)/σ
Where
x = test reults
µ = mean score
σ = standard deviation
From the information given,
µ = 1700 points
σ = 75 points
We want to the probability that a student will score more than 1700 points. This is expressed as
P(x > 1700) = 1 - P(x ≤ 1700)
For x = 1700,
z = (1700 - 1700)/75 = 0/75 = 0
Looking at the normal distribution table, the probability corresponding to the z score is 0.5
P(x > 1700) = 1 - 0.5 = 0.5
Step 1: Multiply 5x2 = 10 so the equation after the first step should look like this 10 + 12x + 8 = 0.
Step 2: Subtract 10 from the 8 and the number by itself cause whatever you do to one side you must do to the other. so the equation should look like this after the second step 12x + -2 = 0 because we subtracted the 10 and the 8.
Step 3: Now we must add the 2 to both sides because we have to do the inverse operation in this problem so once we've done this it should end up looking like this after the 3rd step 12x = 2 because the 2 was a negative.
Step 4: the final step we must divide since an anytime we have a number next to a variable it means multiply but since were using order of operations we have to do the opposite/inverse operation in this problem and we would divide 12 by 2 and get our final answer as x = -6 because the 12 would cancel itself out leaving us with 2 divided by 12 which is 0.16 or -6 depending on if you want it simplified or not the simplified answer would be 0.16 and the non simplified version would be -6
With the help of the ratio method, we conclude that 72 grams of sugar should be added.
<h3>
What is Ratio Method?</h3>
- In the ratio method, we compare two quantities by equating their two ratios; this equation is also referred to as a proportion.
- The cross-multiplication method will be used to solve it.
So, 'n=5' will be the number of rings.
- 'w = 18 grams' will be the weight of each ring.
- Total weight: w₀ = n × w = 5 × 18 = 90 grams
Let 's' be silver. Then,
- New weight: wₙ = s + 90
- Old % of gold: p₀ = 90% = 0.9
- New % of gold: pₙ = 50% = 0.5
Now, use the ratio method as follows:
- 90 × 0.9 = 0.5 × (s + 90)
- 81 = 0.5s + 0.5 × 90
- 81 = 0.5s + 45
- 81 - 45 = 0.5s
- 36 = 0.5s
- 36/0.5 = s
- 72 = s
- So, s = 72
Therefore, with the help of the ratio method, we conclude that 72 grams of sugar should be added.
Know more about Ratio Method here:
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The correct question is given below:
A jeweler has five rings, each weighing 18 grams, made of alloys of 10% silver and 90% gold. He decides to melt down the rings and add enough silver to reduce the gold content to 50%. How much silver should he add?
Answer:
area: 136 cm
perimeter: 48 cm
Step-by-step explanation:
For the first one just subtract
for the second one you just have to break it into smaller, more digestible pieces (work below)
