In recent years more people have been working past the age of 65. in 2005, 27% of people aged 65–69 worked. a recent report from the organization for economic co-operation and development (oecd) claimed that percentage working had increased (usa today, november 16, 2012). the findings reported by the oecd were consistent with taking a sample of 600 people aged 65–69 and finding that 180 of them were working.
a. develop a point estimate of the proportion of people aged 65–69 who are working.

b. set up a hypothesis test so that the rejection of h0 will allow you to conclude that the

proportion of people aged 65–69 working has increased from 2005.

c. conduct your hypothesis test using α 5 .05. what is your conclusion?

a) point estimate is 30%

b) null and alternative hypothesis would be

: p=27%

: p>27%

c) We reject the null hypothesis, percentage working people aged 65-69 had increased

Step-by-step explanation:

a.

Point estimate would be the proportion of the working people aged 65–69 to the sample size and equals ie 30%

b.

Let p be the proportion of people aged 65–69 who is working. OECD claims that percentage working had increased. Then null and alternative hypothesis would be

: p=27%

: p>27%

c.

z-score of the sample proportion assuming null hypothesis is:

where

then z= = 1.655

Since one tailed p value of 1.655 = 0.048 < 0.05, sample proportion is significantly different than the proportion assumed in null hypothesis. Therefore we reject the null hypothesis.

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950