Answer:
357 minutes
Step-by-step explanation:
I subtracted 9 cents/minute from the 23 cents/minute to get 14 cents to get the difference between the two per minute charges. I then divided the monthly cost of $49.95 by .14 to get 356.79... So if you used 357 minutes in a month, the second plan would be 3 cents cheaper at $82.08 (.09 x 357= 32.13 + 49.95), vs. the first plan costing $82.11 (.23 x 357). At 356 minutes the first plan would still be cheaper.
Answer:
x = 1/2 or x = -4
Step-by-step explanation:
Since the product equals zero, use the zero product rule.
(2x - 1)(x + 4) = 0
2x - 1 = 0 or x + 4 = 0
2x = 1 or x = -4
x = 1/2 or x = -4
Answer:
Slope is -2
Step-by-step explanation:
Answer:
4.75% of the bottles are succesful.
Step-by-step explanation:
Problems of normally distributed samples can be 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:
.
If these bottles are shipped 12 to a carton, in what proportion of cartons will at least one of the bottles have a bursting strength exceeding 300 psi?
This proportion is the percentage of the bootles that exceed 300 psi. This is 1 subtracted by the pvalue of Z when
.



has a pvalue of 0.9525.
This means that the proportion of sucesses is 1-0.9525 = 0.0475 = 4.75% of the bottles.