Answer:
Step-by-step explanation:
There are 99 - 10 + 1 = 90 numbers between 10 and 99
There are 18 numbers that have at least one two digit.
Answer:
k = 7
Step-by-step explanation:
given y varies jointly with x and w then the equation relating them is
y = kxw ← k is the constant of variation
to find k use the condition when y = - 42, x = 2 and w = - 3 , then
- 42 = k × 2 × - 3
- 42 = - 6k ( divide both sides by - 6 )
7 = k
constant of variation is k = 7
72 square centimeters because
<span>(12×10)−(8×6)</span>
<span>120−48</span>
<span>72</span>
Answer:
The confidence interval is from 69.82 o 82.18
Step-by-step explanation:
Using this formula X ± Z (s/√n)
Where
X = 76 --------------------------Mean
S = Standard Deviation
If Variance = 144
S = √144
S = 12
n = 25 ----------------------------------Number of observation
Z = 2.576 ------------------------------The chosen Z-value from the confidence table below
Confidence Interval || Z
80%. || 1.282
85% || 1.440
90%. || 1.645
95%. || 1.960
99%. || 2.576
99.5%. || 2.807
99.9%. || 3.291
Substituting these values in the formula
Confidence Interval (CI) = 76 ± 2.576 (12/√25)
CI = 76 ± 2.576(12/5)
CI = 76 ± 2.576(2.4)
CI = 76 ± 6.1824
CI = 76 + 6.1824 ~ 76 - 6.1824
CI = 82.1824 ~ 69.8176
CI = 82.18 ~ 69.82
In other words the confidence interval is from 69.8176 to 82.1824
