The value of x is 50 or 160
Answer:
The mean and standard deviation of the number of questions that each student gets correct are 4 and 1.789 respectively (
(x+ (x+2)+ (x+4) + (x+6) + (x+8) + (x+10))/6 = 22
First let's combine like terms.
(6x+30)/6= 22
Evaluate the division on the left side.
x+5=22
Subtract 5 from both sides
x=17
Final answer: 17
Answer:
The middle slab is 2 cubic feet.
Step-by-step explanation:
The problem presents the information: Mr. Alvarez makes a walkway out of 3 cement slabs.
However, he uses 14 Cubic feet of cement to make the walkway. Each square slab has a volume of 4 cubic feet.
Mr. Alvarez makes the way with 3 cement slabs (NC), each cement slab is 4 cubic feet (UC). It means, the cubic feet for the 3 cement slabs (CS) are:
CS = NC* UC = 3*4 = 12 cubic feet.
It means Mr. Alvarez uses 12 cubic feet with 3 cement slabs.
Mr. Alvarez used in total of 14 cubic feet of cement (TC). At this moment he used 12 cubic feet of cement (CS). It means, there will be a part of the cement slab used (PC).
PC = TC - CS = 14 - 12 = 2 Cubic feet.
Finally, the middle slab is 2 cubic feet of cement.
Answer:
a) 6080 ft
b) 29.952 mph = 30 mph to 2s.f
c) 15.6 knots
Step-by-step explanation:
Length of an arc is given as (θ/360) × (2πr)
For a nautical mile, θ = 1' = (1/60)° = 0.01667°
Length of a nautical mile = (0.01667/360) × (2π × 3960) = 1.152 miles
1 mile = 5280 ft
1.152 miles = 5280×1.152 = 6082.1 ft = 6080 ft to the nearest 10 feet.
b) 1 knot = 1 nautical mile/hour
1 nautical mile/hour = 1.152 miles/hour (from part (a))
1 knot = 1.152 miles/hour
26 knots = 26 × 1.152 miles/hour = 29.952 mph = 30 mph to 2 s.f
c) 1.152 mph = 1 knot
18 mph = (18×1/1.152) knots = 15.625 knots