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#21 in an italian class, 65 percent of the students were women. at the …

Question

#21 in an italian class, 65 percent of the students were women. at the end of the class, 52 percent of the men and 44 percent of the women received a certificate. what percentage of the class received a certificate? (ignore the percent symbol when entering your answer. for example, if the answer is 42.1%, enter 42.1)
#22 what percentage of those who received a certificate were men? (ignore the percent symbol when entering your answer. for example, if the answer is 42.1%, enter 42.1)
#23 the equation p = 215(1.005)^(t/3) can be used to model the population, in thousands, of a certain city t years after 2000. according to the model, the population is predicted to increase by 0.5% every n months. what is the value of n? a) 3 b) 4 c) 12 d) 36
#24 the graph of the exponential function h in the xy - plane, where y = h(x), has a y - intercept of d, where d is a positive constant. which of the following could define the function h? a) h(x)=-3(d)^x b) h(x)=3(x)d c) h(x)=d(-x)^3 d) h(x)=d(3)^x
#25: the scores on the biology test are displayed on a box and whisker plot. 38 72 88 96 102 a) what was the high score on the test? b) what percent of the class scored above a 72? c) what was the median score on the test? d) what percent of the class scored between 88 & 96? e) do you think this is a hard test? explain.
#26: the average minutes per night spent on homework are displayed on the graph. average minutes per night spent on homework 0 20 48 60 190 a) what percent of sophomores spend more than 60 minutes on homework per night? b) what is the range of times that the middle 50% of sophomores spend on homework per night? c) what percent of the sophomores spend less than 20 minutes per night on homework?

Explanation:

Response
#21

Step1: Assume total students as 100

Let the total number of students be 100. Then the number of women is $0.65\times100 = 65$ and the number of men is $100 - 65=35$.

Step2: Calculate number of men and women with certificates

Number of men with certificates is $0.52\times35 = 18.2$. Number of women with certificates is $0.44\times65 = 28.6$.

Step3: Calculate total number of students with certificates

Total number of students with certificates is $18.2 + 28.6=46.8$.

Step1: Use results from #21

From #21, number of men with certificates is 18.2 and total with certificates is 46.8.

Step2: Calculate percentage of men among certificate - receivers

Percentage is $\frac{18.2}{46.8}\times100\approx38.9$.

Step1: Recall compound - interest formula

The general compound - interest formula is $A = P(1 + r)^n$, where $r$ is the rate of interest per period and $n$ is the number of periods. Here, the population formula is $P = 215(1.005)^{\frac{t}{n}}$. The annual growth rate is $r = 0.005$ (or 0.5%).

Step2: Determine the number of periods in a year

If the population increases by 0.5% every $n$ months, in 12 months, the number of $n$ - month periods is $\frac{12}{n}$. And the growth factor in 1 year is $(1 + 0.005)^{\frac{12}{n}}$. For an annual growth rate of 0.5%, we know that if we consider the growth in 1 year, when $t = 1$, the formula $P = 215(1.005)^{\frac{t}{n}}$ should represent the annual growth. Since the growth rate is 0.5% per $n$ months, and in 12 months the growth is also based on this $n$ - month increment. If we assume the number of $n$ - month periods in 12 months, and the growth factor per $n$ - month period is 1.005, we want $(1.005)^{\frac{12}{n}}$ to represent the annual growth. Since the growth rate is 0.5% per $n$ - month period and we know that for an annual growth of 0.5%, the number of $n$ - month periods in a year should be 1. So $\frac{12}{n}=1$, which gives $n = 12$.

Answer:

46.8

#22