Answer:
2.4 hours
Step-by-step explanation:
Let total work = X
Rate of work done = X ÷ time
Rate of A = X/4
Rate of B = X/6
If they work together, rate is the sum of their individual rates, i.e.
X/4 + X/6
= (3X + 2X)/12 (taking LCM)
=5X/12
Rate = X/time
5X/12 = X/time
time = X÷(5X/12)
time = X × 12/(5X)
time = 2.4 hours
Shortcut:
Product of individual times/sum of individual times
= (4×6)/(4+6)
=24/10
=2.4 hours
Answer:
Step-by-step explanation:
Slope = (y2 -y1)/(x2-x1)
y2 = 800, y1 = 400, x2= 4, x1= 2
Slope = (800-400)/(4-2)
= 400/2
= 200calories/hr
Using the normal distribution, the area underneath the shaded region <u>between the two z-scores</u> is given by:
C. 0.6766.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean 
and standard deviation 
is given by:
- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
Hence, for this problem, the area is the <u>p-value of z = 0.75 subtracted by the p-value of z = -1.3</u>.
Looking at the z-table, the p-values are given as follows:
Then:
0.7734 - 0.0968 = 0.6766.
Which means that option C is correct.
More can be learned about the normal distribution at brainly.com/question/15181104
#SPJ1
Answer:
6.34 × 10²
Step-by-step explanation:
Calculating scientific notation for a positive integer is simple, as it always follows this notation: a x 10b.
Step 1
To find a, take the number and move a decimal place to the right one position.
Original Number: 634
New Number: 6.34
Step 2
Now, to find b, count how many places to the right of the decimal.
New Number: 6 . 3 4
Decimal Count: 1 2
There are 2 places to the right of the decimal place.
Step 3
Building upon what we know above, we can now reconstruct the number into scientific notation.
Remember, the notation is: a x 10b
a = 6.34
b = 2
Now the whole thing:
6.34 x 10²
Step 4
Check your work:
10² = 100 x 6.34 = 634
X will equal 10 and y will equal 7
