Answer:
P(x< 18) = 0.986
Step-by-step explanation:
Step 1: find the z-score using the formula, z = (x - µ)/σ
Where,
x = randomly chosen values = 18
µ = mean = 7
σ = standard deviation = 5
Proportion of the population that is less than 18 = P(x < 18)
Plug in the values into z = (x - µ)/σ, to get z-score.
z = (18 - 7)/5
z = 11/5 = 2.2
Step 2: Find P(x< 18) = P (z<2.2) using z-table.
The probability that corresponds with z-score calculated is 0.986.
Therefore,
P(x< 18) = 0.986
21) Since all angles = 180,
180=66 + 79 + (43 + x)
Subtract (66 + 79) from both sides, you’d get
35= 43 + x
subtract 43 from both sides and x = -8
We observe that 20 is 4 more than twice 8. This suggests the time is 1 hour and the rates are
... scooter: 20 mi/h
... bicycle: 8 mi/h
_____
You can let b represent the rate of the bicycle in miles per hour. Then we have (for time in hours and distance in miles) ...
... time = distance/speed
... time = 20/(2b+4) = 8/b
... 20b = 8(2b+4) = 16b +32
... 4b = 32
... b = 8
The rate of the bicycle is 8 mph; that of the scooter is 2*8+4 = 20 mph.
The median of variable A is the middle value when the all the values for variable A is arranged from smallest to greatest.
The values for variable A are
1, 2, 4, 4, 5, 6, 7, 9
The middle value is between 4 and 5. The median is between 4 and 5.
(4 + 5) /2 = 4.5
The median is 4.5