Answer:
The difference is $10
Step-by-step explanation:
we know that
The cost of the Unlimited Talk Plan is $99.99 per month
The total cost for 1,420 minutes with plan C is equal to
$79.99+(1,420-1,400)*$0.50=$89.99
The difference is equal to
$99.99-$89.99=$10
Answer:
30°
Step-by-step explanation:
∠A + ∠B + ∠C = 180
∠B = ∠A + 20
∠C = 2 * ∠B
<A + (∠A + 20) + (2 * ∠B) = 180
<A + (∠A + 20) + (2 * (∠A + 20)) = 180
<A + (∠A + 20) + 2∠A + 40 = 180
4∠A + 60 = 180
4∠A = 120
∠A = 30
Answer:
82% of scores were between 286 and 322
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean and standard deviation , the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of 310 and a standard deviation of 12.
This means that
What percent of scores were between 286 and 322?
The proportion is the pvalue of Z when X = 322 subtracted by the pvalue of Z when X = 286. So
X = 322
has a pvalue of 0.8413
X = 286
has a pvalue of 0.0228
0.8413 - 0.0228 = 0.8185
0.8185*100% = 81.85%
Rounding to the nearest whole number
82% of scores were between 286 and 322