a and b i hope this is correct
Answer:
The approximate percentage of SAT scores that are less than 865 is 16%.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 1060, standard deviation of 195.
Empirical Rule to estimate the approximate percentage of SAT scores that are less than 865.
865 = 1060 - 195
So 865 is one standard deviation below the mean.
Approximately 68% of the measures are within 1 standard deviation of the mean, so approximately 100 - 68 = 32% are more than 1 standard deviation from the mean. The normal distribution is symmetric, which means that approximately 32/2 = 16% are more than 1 standard deviation below the mean and approximately 16% are more than 1 standard deviation above the mean. So
The approximate percentage of SAT scores that are less than 865 is 16%.
You didn’t add any pictures so how could i help you with this?
Answer:
x = 15 or x = - 
Step-by-step explanation:
Cross- multiplying gives
(14x + 6)(17x + 5) = 9x(27x + 11) ( expanding factors )
238x² + 172x + 30 = 243x² + 99x
rearrange into standard form : ax² + bx + c = 0
5x² - 73x - 30 = 0 ← in standard form
consider the factors of the product 5 × - 30 = - 150 which sum to the coefficient of the x-term (- 73 )
the factors are - 75 and + 2
Use these factors to split the middle term
5x² - 75x + 2x - 30 = 0 ( factor by grouping )
5x(x - 15) + 2(x - 15) = 0 ← take out the factor (x - 15)
(x - 15)(5x + 2) = 0
equate each factor to zero and solve for x
x - 15 = 0 ⇒ x = 15
5x + 2 = 0 ⇒ x = -
Factors of 9: 1; 3; 9
Factors of 36: 1; 2; 3; 4; 6; 9; 12; 18; 36
GCF(9; 36) = 9
