Answer:
Lower limit: 113.28
Upper limit: 126.72
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 problem, we have that:
Middle 60%
So it goes from X when Z has a pvalue of 0.5 - 0.6/2 = 0.2 to X when Z has a pvalue of 0.5 + 0.6/2 = 0.8
Lower limit
X when Z has a pvalue of 0.20. So X when 
Upper limit
X when Z has a pvalue of 0.80. So X when 
Answer: 7 laps
Step-by-step explanation:
The athlete planned to run 3 miles
1 lap = 3/7 miles
x laps = 3 miles
by proportion :
x × 3/7miles = 3 miles
x = 3 ÷ 3/7
x = 3 x 7/3
x = 7
Therefore: the athlete will run 7 laps
9514 1404 393
Answer:
5 hours
Step-by-step explanation:
A quick way to look at this is to compare the difference in hourly charge to the difference in 0-hour charge.
The first day, the charge is $3 more than $12 per hour.
The second day, the charge is $12 less than $15 per hour.
The difference in 0-hour charges is 3 -(-12) = 15. The difference in per-hour charges is 15 -12 = 3. The ratio of these is ...
$15/($3/h) = 5 h
The charges are the same after 5 hours.
__
If you write equations for the charges, they will look like ...
y1 = 15 + 12(x -1)
y2 = 3 + 15(x -1)
Equating these charges, we have ...
15 +12(x -1) = 3 + 15(x -1)
12x +3 = 15x -12 . . . . . . . . eliminate parentheses
15 = 3x . . . . . . . . . . add 12-12x
x = 15/3 = 5 . . . . . . divide by 3
You might notice that the math here is very similar to that described in words, above.
The charges are the same after 5 hours.
Answer:
(i) ∠ABH = 14.5°
(ii) The length of AH = 4.6 m
Step-by-step explanation:
To solve the problem, we will follow the steps below;
(i)Finding ∠ABH
first lets find <HBC
<BHC + <HBC + <BCH = 180° (Sum of interior angle in a polygon)
46° + <HBC + 90 = 180°
<HBC+ 136° = 180°
subtract 136 from both-side of the equation
<HBC+ 136° - 136° = 180° -136°
<HBC = 44°
lets find <ABC
To do that, we need to first find <BAC
Using the sine rule
= 
A = ?
a=6.9
C=90
c=13.2
= 
sin A = 6.9 sin 90 /13.2
sinA = 0.522727
A = sin⁻¹ ( 0.522727)
A ≈ 31.5 °
<BAC = 31.5°
<BAC + <ABC + <BCA = 180° (sum of interior angle of a triangle)
31.5° +<ABC + 90° = 180°
<ABC + 121.5° = 180°
subtract 121.5° from both-side of the equation
<ABC + 121.5° - 121.5° = 180° - 121.5°
<ABC = 58.5°
<ABH = <ABC - <HBC
=58.5° - 44°
=14.5°
∠ABH = 14.5°
(ii) Finding the length of AH
To find length AH, we need to first find ∠AHB
<AHB + <BHC = 180° ( angle on a straight line)
<AHB + 46° = 180°
subtract 46° from both-side of the equation
<AHB + 46°- 46° = 180° - 46°
<AHB = 134°
Using sine rule,
= 
AH = 13.2 sin 14.5 / sin 134
AH≈4.6 m
length AH = 4.6 m
Answer:
pounds (lb)
Step-by-step explanation:
