Answer:
Step-by-step explanation:
Answer:
4.05% probability that a randomly selected adult has an IQ greater than 123.4.
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:

Probability that a randomly selected adult has an IQ greater than 123.4.
This is 1 subtracted by the pvalue of Z when X = 123.4. So



has a pvalue of 0.9595
1 - 0.9595 = 0.0405
4.05% probability that a randomly selected adult has an IQ greater than 123.4.
The 2 fractions are the possibilities
Answer:
2. x = 47
3. x = 2
Step-by-step explanation:
These problems involve proportions, or equivalent ratios. You can solve for 'x' in each by using cross-multiplication and division.
2. 28(7) = 4(x + 2)
Distribute = 196 = 4x + 8
Subtract 8 from both sides: 196 - 8 = 4x + 8 - 8 or 188 = 4x
Solve for x: x = 47
3. 2(2x + 7) = 11(3x - 4)
Distribute: 4x + 14 = 33x - 44
Add 44 to both sides: 4x + 14 + 44 = 33x - 44 + 44 or 4x + 58 = 33x
Subtract 4x from both sides: 4x + 58 - 4x = 33x - 4x or 58 = 29x
Solve for x: x = 2
4c+5.6d=1360
Let
Children (c)=x
Adults (d)=284-x
4x+5.6 (284-x)=1360
Solve for x
4x+1590.4-5.6x=1360
4x-5.6x=1360-1590.4
-1.6x=-230.4
X=230.4÷1.6
X=144 children
284−144=140 adults