Answer:
38 mpg
Step-by-step explanation:
Initial efficiency = 39 mpg
Initial speed = 40 mph
Final speed = 50 mph
The efficiency drop between 40 mph and 50 mph is given by:

The total efficiency drop from 40 to 50 mph is:

Therefore, the efficiency at 50 mph is:

Answer:
$246.75
Step-by-step explanation:
A student earns $11.75 for 1 hour
If she works for 21 hours this month then the total amount earned can be calculated as follows
= 11.75 × 21
= 246.75
Hence the total amount earned this month is $246.75
Answer:
a) 0.283 or 28.3%
b) 0.130 or 13%
c) 0.4 or 40%
d) 30.6 mm
Step-by-step explanation:
z-score of a single left atrial diameter value of healthy children can be calculated as:
z=
where
- X is the left atrial diameter value we are looking for its z-score
- M is the mean left atrial diameter of healthy children (26.7 mm)
- s is the standard deviation (4.7 mm)
Then
a) proportion of healthy children who have left atrial diameters less than 24 mm
=P(z<z*) where z* is the z-score of 24 mm
z*=
≈ −0.574
And P(z<−0.574)=0.283
b) proportion of healthy children who have left atrial diameters greater than 32 mm
= P(z>z*) = 1-P(z<z*) where z* is the z-score of 32 mm
z*=
≈ 1.128
1-P(z<1.128)=0.8703=0.130
c) proportion of healthy children have left atrial diameters between 25 and 30 mm
=P(z(25)<z<z(30)) where z(25), z(30) are the z-scores of 25 and 30 mm
z(30)=
≈ 0.702
z(25)=
≈ −0.362
P(z<0.702)=0.7587
P(z<−0.362)=0.3587
Then P(z(25)<z<z(30)) =0.7587 - 0.3587 =0.4
d) to find the value for which only about 20% have a larger left atrial diameter, we assume
P(z>z*)=0.2 or 20% where z* is the z-score of the value we are looking for.
Then P(z<z*)=0.8 and z*=0.84. That is
0.84=
solving this equation for X we get X=30.648
Answer:
32
Step-by-step explanation:
The equation
and the graph below describe the velocity V in feet per second of a ball <em>t</em> seconds after it is shot into the air.
To find the balls velocity after seven seconds, substitute t = 7 into the function expression:

You question isn't clear, but I assume that you are asking for the slop of a line parallel to y=-(5/4)(x)+7.
The line parallel would have a slop of -5/7 and the line perpendicular would have a slop of 5/7.
The difference between the two answers is the sign of the two slopes, one is positive the other is negative