Answer:
The answer in interval notation is ( 73 , 100 )
Step-by-step explanation:
If we call x and y the lower and upper values for David to get an average of 80 and 89 respectively, we can calculate these two values solving a pair of equations:
(81 + 92 + 74 + x ) / 4 = 80 ⇒ (247 + x )/4 = 80
247 + x = 320 ⇒ x = 320 - 247
x = 73
And
(81 + 92 + 74 + y ) / 4 = 89 ⇒ ( 247 + y ) / 4 = 89
247 + y = 356
y = 356 - 247
y = 109
But tests are a 100-point test
Then the answer in interval notation is ( 73 , 100 )
Answer:
Step-by-step explanation:
R' (3,5)
S' (2,2)
T' (5,3)
Ok, it's all pretty much like the "$50 coat is on sale for $35".
<span>If the regular price of the coat is $50 and now it is on sale for $35, then it will cost you $15 less, like this: </span>
<span>$50 - $35 = $15 </span>
<span>You could also say the coat was discounted by $15, or the coat was reduced by $15, or you'll save $15 if you buy that coat ($50 - $15 = 35). </span>
<span>You could also put it in terms of percentages. If the discount is $15, you can figure that $15 is what percent of the regular price, like this: </span>
<span>$15 = X% of $50 </span>
<span>$15 = X% x $50 (divide both sides by 50 to isolate X) </span>
<span>15/50 = X% </span>
<span>.30 = X% (multiply by 100 to convert to a non-decimal) </span>
<span>30% = X </span>
<span>So, you can say all of the following and they all mean the same thing: </span>
<span>1. the $50 coat is on sale for $35 </span>
<span>2. the $50 coat is discounted by $15 </span>
<span>3. the $50 coat is reduced by $15 </span>
<span>4. you'll save $15 if you buy this coat </span>
<span>5. the $50 coat is on sale for 30% off </span>
<span>6. the $50 coat is discounted by 30% </span>
<span>7. you'll save 30% if you buy this coat </span>
<span>8. 30% savings! </span>
<span>9. Save 30%! </span>
<span>So, how does that apply to the $18,000 a year? Ok, if Shelby earns $18,000 this year and then earns $19,500 next year, then she gets an additional $1,500 ($19,500 - $18,000 = $1,500). In the coat problem, everything was discounted, on sale, going down. In this problem, everything is going up, increasing. </span>
<span>You know the dollar increase is $1,500. To figure the percent increase, you need to figure out that $1,500 is what % of $18,000. Remember, it's not the $19,500 that was increased; it was an increase on the $18,000: </span>
<span>$1,500 = X% of $18,000 </span>
<span>1,500/18,000 = X% </span>
<span>.083333 = X% </span>
<span>8.3333% = X </span>
<span>One more: If Shelby get a 10% increase in her salary at the end of one year, that's the same as saying that Shelby gets her salary plus she gets 10% more, like this: </span>
<span>$18,000 + (10% of $18,000) = </span>
<span>$18,000 + $1,800 = </span>
<span>$19,800 end of first year </span>
<span>For the second year, her salary begins at $19,800 and increases 10%, like this: </span>
<span>$19,800 + (10% x $19,800) = </span>
<span>$19,800 + $1,980 = </span>
<span>$21,780 end of second year </span>
<span>You can do it from here.</span>
<span>120 miles----------------------1 hour.
45 miles ----------------------?? x hours
x= 45 / 120 = 0.375 hours
</span>
