Answer:
a) The first inequality is 100 + 55x > 150 + 51x;
b) The final inequality results in x > 12.5
c) Sal's mother will need to use the second phone for at least 13 months.
Step-by-step explanation:
a) Let x represent the number of months.
1. The first phone is priced at $100, with a monthly fee of $55 for unlimited use, leading to a total cost of $(100 + 55x) for x months.
2. The second phone costs $150 with a monthly fee of $51 for unlimited use, resulting in a total of $(150 + 51x) for x months.
3. For the second phone to be cheaper, we set up the inequality:
150 + 51x < 100 + 55x
which simplifies to
100 + 55x > 150 + 51x
b) Now solve this:
55x - 51x > 150 - 100
4x > 50
so x > 12.5
c) This means Sal's mother has to retain the second phone for at least 13 months (since x > 12.5).
Each LED bulb, along with installation labor, is priced at
.. $6.95 +$3 = $9.95
For 100 bulbs over a span of 10 years, that equals (100*10) = 1000 bulb·years. At $9.95 per bulb, 5 bulb·years are obtained, and thus the projected total cost for 1000 bulb·years is
.. (1000 b·y)*($9.95/(5 b·y)) = $1990
In summary, for a decade, the installation and changes of 200 bulbs in 100 lamps amount to $1990. Therefore, the yearly cost is...
.. $1990/(10 yr) = $199/yr
E. All of the other options provided are incorrect. Step-by-step explanation: ANOVA, or analysis of variance, is employed to evaluate the variances among group averages within a dataset. The sum of squares is regarded as the total of squared deviations, defined as the distance between each individual observation and the overall mean. Assuming there are groups comprised of individuals, we can articulate the relevant variance formulas. In this instance, the numerator's degrees of freedom can be calculated as k - 1, where k equals the five groups. The denominator's degrees of freedom are determined through n - k, where n reflects the total number of observations across all groups. For this scenario, the numerator yields 4 and the denominator results in 95. Hence, E. None of the above answers is correct.
